Organic iridium compositions and their use in electronic devices

ABSTRACT

The present invention provides compositions comprising at least one novel organic iridium compound which comprises at least one cyclometallated ligand and at least one ketopyrrole ligand. The organic iridium compositions of the present invention are referred to as Type (1) organic iridium compositions and are constituted such that no ligand of the novel organic iridium compound has a number average molecular weight of 2,000 grams per mole or greater (as measured by gel permeation chromatography). Type (1) organic iridium compositions are referred to herein as comprising “organic iridium complexes”. The novel organic iridium compositions are useful in optoelectronic electronic devices such as OLED devices and photovoltaic devices. In one aspect, the invention provides novel organic iridium compositions useful in the preparation of OLED devices exhibiting enhanced color properties and light output efficiencies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to currently pending U.S. ProvisionalApplication Ser. No. 60/833,935, filed Jul. 28, 2006.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT

This invention was made with Government support under contract numberDE-FC26-05NT42343. The Government has certain rights in the invention.

BACKGROUND

The invention includes embodiments that relate to organic iridiumcompositions, intermediates for the preparation of organic iridiumcompositions, and devices which incorporate organic iridiumcompositions. The invention includes embodiments that relate to organiciridium compositions useful as phosphor compositions.

Organic light emitting devices (OLEDs), which make use of thin filmmaterials that emit light when subjected to a voltage bias, are expectedto become an increasingly popular form of flat panel display technology.This is because OLEDs have a wide variety of potential applications,including cellphones, personal digital assistants (PDAs), computerdisplays, informational displays in vehicles, television monitors, aswell as light sources for general illumination. Due to their brightcolors, wide viewing angle, compatibility with full motion video, broadtemperature ranges, thin and conformable form factor, low powerrequirements and the potential for low cost manufacturing processes,OLEDs are seen as a future replacement technology for cathode ray tubes(CRTs) and liquid crystal displays (LCDs). Due to their high luminousefficiencies, OLEDs are seen as having the potential to replaceincandescent, and perhaps even fluorescent, lamps for certain types ofapplications.

Light emission from OLEDs typically occurs via electrofluorescence, i.e.light emission from a singlet excited state formed by applying a voltagebias across a ground state electroluminescent material. It is believedthat OLEDs capable of producing light by an alternate mechanism,electrophosphorescence, i.e. light emission from a triplet excited stateformed by applying a voltage bias across a ground stateelectrofluorescecent material, will exhibit substantially higher quantumefficiencies than OLEDs that produce light primarily byelectrofluorescence. Light emission from OLEDs by electrophosphorescenceis limited since the triplet excited states in most light emittingorganic materials are strongly disposed to non-radiative relaxation tothe ground state. Thus, electrophosphorescent materials hold promise askey components of OLED devices and other optoelectronic devicesexhibiting greater efficiencies relative to the current state of theart. For example, OLEDs capable of light production byelectrophosphorescence are expected to exhibit a reduction (relative toOLEDs which produce light primarily by electrofluorescence) in theamount of energy lost to radiationless decay processes within the devicethereby providing an additional measure of temperature control duringoperation of the OLED.

Improved light emission efficiencies have been achieved by incorporatinga phosphorescent platinum-containing dye in an organicelectroluminescent device such as an OLED (See Baldo et al., “HighlyEfficient Phosphorescent Emission from Organic ElectroluminescentDevices”, Nature, vol. 395, 151-154, 1998) and phosphorescentiridium-containing dyes have also been employed (See for example Leclouxet al. United States Patent Application 20030096138, May 22, 2003).Notwithstanding earlier developments, there is currently considerableinterest in finding novel phosphorescent materials which not onlyincrease efficiency but also provide for a greater measure of control ofthe color of light produced by an OLED. For example, it would be highlydesirable to provide novel phosphorescent materials which enable organicelectroluminescent devices having improved overall efficiency, while atthe same time allowing for the light output to be red shifted or blueshifted, depending on the nature of the application.

BRIEF DESCRIPTION

The invention provides a novel class of organic iridium compounds, anddemonstrates the utility of these materials in organicelectroluminescent devices. Thus, in one embodiment, the inventionprovides a composition comprising at least one organic iridium complexcomprising:

(i) at least one cyclometallated ligand; and

(ii) at least one ketopyrrole ligand.

In another embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex comprising:

(i) at least one cyclometallated ligand; and

(ii) at least one ketopyrrole ligand.

In yet another embodiment, the present invention provides an organiciridium complex having structure XIV.

These and other features, aspects, and advantages of the presentinvention may be more understood more readily by reference to thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents an OLED device provided by the present invention.

FIG. 2 represents an OLED device provided by the present invention.

FIG. 3 represents an OLED device provided by the present invention.

FIG. 4 represents an OLED device provided by the present invention.

FIG. 5 represents an OLED device provided by the present invention.

FIG. 6 represents an OLED device provided by the present invention.

FIG. 7 represents an OLED device provided by the present invention.

FIG. 8 represents an OLED device provided by the present invention.

FIG. 9 represents an OLED device provided by the present invention.

FIG. 10 represents an OLED device provided by the present invention.

FIG. 11 represents an OLED device provided by the present invention.

FIG. 12 illustrates the photoluminescent behavior of a film comprisingan organic iridium complex provided by the present invention and twofilms comprising reference compounds.

FIG. 13 illustrates the electroluminescence spectra of two OLED devicesprovided by the present invention and a reference OLED device.

FIG. 14 illustrates a plot of lumens per watt (LPW) versus voltage oftwo OLED devices of the present invention and a reference OLED device.

FIG. 15 illustrates a plot of relative brightness in candela per Ampere(cd/A) versus voltage of two OLED devices of the present invention and areference OLED device.

DETAILED DESCRIPTION

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about” and “substantially”, are not to be limited tothe precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value. Here and throughout the specification andclaims, range limitations may be combined and/or interchanged, suchranges are identified and include all the sub-ranges contained thereinunless context or language indicates otherwise.

As used herein, the term “aromatic radical” refers to an array of atomshaving a valence of at least one comprising at least one aromatic group.The array of atoms having a valence of at least one comprising at leastone aromatic group may include heteroatoms such as nitrogen, sulfur,selenium, silicon and oxygen, or may be composed exclusively of carbonand hydrogen. As used herein, the term “aromatic radical” includes butis not limited to phenyl, pyridyl, furanyl, thienyl, naphthyl,phenylene, and biphenyl radicals. As noted, the aromatic radicalcontains at least one aromatic group. The aromatic group is invariably acyclic structure having 4n+2 “delocalized” electrons where “n” is aninteger equal to 1 or greater, as illustrated by phenyl groups (n=1),thienyl groups (n=1), furanyl groups (n=1), naphthyl groups (n=2),azulenyl groups (n=2), anthracenyl groups (n=3) and the like. Thearomatic radical may also include nonaromatic components. For example, abenzyl group is an aromatic radical which comprises a phenyl ring (thearomatic group) and a methylene group (the nonaromatic component).Similarly a tetrahydronaphthyl radical is an aromatic radical comprisingan aromatic group (C₆H₃) fused to a nonaromatic component —(CH₂)₄—. Forconvenience, the term “aromatic radical” is defined herein to encompassa wide range of functional groups such as alkyl groups, alkenyl groups,alkynyl groups, haloalkyl groups, haloaromatic groups, conjugated dienylgroups, alcohol groups, ether groups, aldehyde groups, ketone groups,carboxylic acid groups, acyl groups (for example carboxylic acidderivatives such as esters and amides), amine groups, nitro groups, andthe like. For example, the 4-methylphenyl radical is a C₇ aromaticradical comprising a methyl group, the methyl group being a functionalgroup which is an alkyl group. Similarly, the 2-nitrophenyl group is aC₆ aromatic radical comprising a nitro group, the nitro group being afunctional group. Aromatic radicals include halogenated aromaticradicals such as 4-trifluoromethylphenyl,hexafluoroisopropylidenebis(4-phen-1-yloxy) (i.e., —OPhC(CF₃)₂PhO—),4-chloromethylphen-1-yl, 3-trifluorovinyl-2-thienyl,3-trichloromethylphen-1-yl (i.e., 3-CCl₃Ph-),4-(3-bromoprop-1-yl)phen-1-yl (i.e., 4-BrCH₂CH₂CH₂Ph-), and the like.Further examples of aromatic radicals include 4-allyloxyphen-1-oxy,4-aminophen-1-yl (i.e., 4-H₂NPh-), 3-aminocarbonylphen-1-yl (i.e.,NH₂COPh-), 4-benzoylphen-1-yl, dicyanomethylidenebis(4-phen-1-yloxy)(i.e., —OPhC(CN)₂PhO—), 3-methylphen-1-yl, methylenebis(4-phen-1-yloxy)(i.e., —OPhCH₂PhO—), 2-ethylphen-1-yl, phenylethenyl,3-formyl-2-thienyl, 2-hexyl-5-furanyl,hexamethylene-1,6-bis(4-phen-1-yloxy) (i.e., —OPh(CH₂)₆PhO—),4-hydroxymethylphen-1-yl (i.e., 4-HOCH₂Ph-), 4-mercaptomethylphen-1-yl(i.e., 4-HSCH₂Ph-), 4-methylthiophen-1-yl (i.e., 4-CH₃SPh-),3-methoxyphen-1-yl, 2-methoxycarbonylphen-1-yloxy (e.g., methylsalicyl), 2-nitromethylphen-1-yl (i.e., 2-NO₂CH₂Ph),3-trimethylsilylphen-1-yl, 4-t-butyldimethylsilylphenl-1-yl,4-vinylphen-1-yl, vinylidenebis(phenyl), and the like. The term “aC₃-C₁₀ aromatic radical” includes aromatic radicals containing at leastthree but no more than 10 carbon atoms. The aromatic radical1-imidazolyl(C₃H₂N₂—) represents a C₃ aromatic radical. The benzylradical (C₇H₇—) represents a C₇ aromatic radical.

As used herein the term “cycloaliphatic radical” refers to a radicalhaving a valence of at least one, and comprising an array of atoms whichis cyclic but which is not aromatic. As defined herein a “cycloaliphaticradical” does not contain an aromatic group. A “cycloaliphatic radical”may comprise one or more noncyclic components. For example, acyclohexylmethyl group (C₆H₁₁CH₂—) is a cycloaliphatic radical whichcomprises a cyclohexyl ring (the array of atoms which is cyclic butwhich is not aromatic) and a methylene group (the noncyclic component).The cycloaliphatic radical may include heteroatoms such as nitrogen,sulfur, selenium, silicon and oxygen, or may be composed exclusively ofcarbon and hydrogen. For convenience, the term “cycloaliphatic radical”is defined herein to encompass a wide range of functional groups such asalkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups,conjugated dienyl groups, alcohol groups, ether groups, aldehyde groups,ketone groups, carboxylic acid groups, acyl groups (for examplecarboxylic acid derivatives such as esters and amides), amine groups,nitro groups, and the like. For example, the 4-methylcyclopent-1-ylradical is a C₆ cycloaliphatic radical comprising a methyl group, themethyl group being a functional group which is an alkyl group.Similarly, the 2-nitrocyclobut-1-yl radical is a C₄ cycloaliphaticradical comprising a nitro group, the nitro group being a functionalgroup. A cycloaliphatic radical may comprise one or more halogen atomswhich may be the same or different. Halogen atoms include, for example;fluorine, chlorine, bromine, and iodine. Cycloaliphatic radicalscomprising one or more halogen atoms include2-trifluoromethylcyclohex-1-yl, 4-bromodifluoromethylcyclooct-1-yl,2-chlorodifluoromethylcyclohex-1-yl,hexafluoroisopropylidene-2,2-bis(cyclohex-4-yl) (i.e., —C₆HoC(CF₃)₂C₆H₁₀—), 2-chloromethylcyclohex-1-yl,3-difluoromethylenecyclohex-1-yl, 4-trichloromethylcyclohex-1-yloxy,4-bromodichloromethylcyclohex-1-ylthio, 2-bromoethylcyclopent-1-yl,2-bromopropylcyclohex-1-yloxy (e.g., CH₃CHBrCH₂C₆H₁₀O—), and the like.Further examples of cycloaliphatic radicals include4-allyloxycyclohex-1-yl, 4-aminocyclohex-1-yl (i.e., H₂C₆H₁₀—),4-aminocarbonylcyclopent-1-yl (i.e., NH₂COC₅H₈-),4-acetyloxycyclohex-1-yl, 2,2-dicyanoisopropylidenebis(cyclohex-4-yloxy)(i.e., —OC₆H₁₀C(CN)₂C₆H₁₀O—), 3-methylcyclohex-1-yl,methylenebis(cyclohex-4-yloxy) (i.e., —OC₆H₁₀CH₂C₆H₁₀O—),1-ethylcyclobut-1-yl, cyclopropylethenyl, 3-formyl-2-terahydrofuranyl,2-hexyl-5-tetrahydrofuranyl, hexamethylene-1,6-bis(cyclohex-4-yloxy)(i.e., —OC₆H₁₀(CH₂)₆C₆H₁₀O—), 4-hydroxymethylcyclohex-1-yl (i.e.,4-HOCH₂C₆H₁₀—), 4-mercaptomethylcyclohex-1-yl (i.e., 4-HSCH₂C₆H₁₀—),4-methylthiocyclohex-1-yl (i.e., 4-CH₃SC₆H₁₀—), 4-methoxycyclohex-1-yl,2-methoxycarbonylcyclohex-1-yloxy(2-CH₃OCOC₆H₁₀O—),4-nitromethylcyclohex-1-yl (i.e., NO₂CH₂C₆H₁₀—),3-trimethylsilylcyclohex-1-yl, 2-t-butyldimethylsilylcyclopent-1-yl,4-trimethoxysilylethylcyclohex-1-yl (e.g., (CH₃O)₃SiCH₂CH₂C₆H₁₀—),4-vinylcyclohexen-1-yl, vinylidenebis(cyclohexyl), and the like. Theterm “a C₃-C₁₀ cycloaliphatic radical” includes cycloaliphatic radicalscontaining at least three but no more than 10 carbon atoms. Thecycloaliphatic radical 2-tetrahydrofuranyl(C₄H₇O—) represents a C₄cycloaliphatic radical. The cyclohexylmethyl radical (C₆H₁₁CH₂—)represents a C₇ cycloaliphatic radical.

As used herein the term “aliphatic radical” refers to an organic radicalhaving a valence of at least one consisting of a linear or branchedarray of atoms which is not cyclic. Aliphatic radicals are defined tocomprise at least one carbon atom. The array of atoms comprising thealiphatic radical may include heteroatoms such as nitrogen, sulfur,silicon, selenium and oxygen or may be composed exclusively of carbonand hydrogen. For convenience, the term “aliphatic radical” is definedherein to encompass, as part of the “linear or branched array of atomswhich is not cyclic” a wide range of functional groups such as alkylgroups, alkenyl groups, alkynyl groups, haloalkyl groups, conjugateddienyl groups, alcohol groups, ether groups, aldehyde groups, ketonegroups, carboxylic acid groups, acyl groups (for example carboxylic acidderivatives such as esters and amides), amine groups, nitro groups, andthe like. For example, the 4-methylpent-1-yl radical is a C₆ aliphaticradical comprising a methyl group, the methyl group being a functionalgroup which is an alkyl group. Similarly, the 4-nitrobut-1-yl group is aC₄ aliphatic radical comprising a nitro group, the nitro group being afunctional group. An aliphatic radical may be a haloalkyl group whichcomprises one or more halogen atoms which may be the same or different.Halogen atoms include, for example; fluorine, chlorine, bromine, andiodine. Aliphatic radicals comprising one or more halogen atoms includethe alkyl halides trifluoromethyl, bromodifluoromethyl,chlorodifluoromethyl, hexafluoroisopropylidene, chloromethyl,difluorovinylidene, trichloromethyl, bromodichloromethyl, bromoethyl,2-bromotrimethylene (e.g., —CH₂CHBrCH₂—), and the like. Further examplesof aliphatic radicals include allyl, aminocarbonyl (i.e., —CONH₂),carbonyl, 2,2-dicyanoisopropylidene (i.e., —CH₂C(CN)₂CH₂—), methyl(i.e., —CH₃), methylene (i.e., —CH₂—), ethyl, ethylene, formyl (i.e.,—CHO), hexyl, hexamethylene, hydroxymethyl (i.e., —CH₂OH),mercaptomethyl (i.e., —CH₂SH), methylthio (i.e., —SCH₃),methylthiomethyl (i.e., —CH₂SCH₃), methoxy, methoxycarbonyl (i.e.,CH₃OCO—), nitromethyl (i.e., —CH₂NO₂), thiocarbonyl, trimethylsilyl(i.e., (CH₃)₃Si—), t-butyldimethylsilyl, 3-trimethyoxysilypropyl (i.e.,(CH₃O)₃SiCH₂CH₂CH₂—), vinyl, vinylidene, and the like. By way of furtherexample, a C₁-C₁₀ aliphatic radical contains at least one but no morethan 10 carbon atoms. A methyl group (i.e., CH₃—) is an example of a C₁aliphatic radical. A decyl group (i.e., CH₃(CH₂)₉—) is an example of aC₁₀ aliphatic radical.

As used herein, the term “electroactive material” refers to organicmaterials which may be polymeric or non-polymeric, and which aresusceptible to charge conduction when subjected to a voltage bias, forexample organic materials which conduct electrons and/or holes in anorganic light emitting device (OLED). Electroactive materials include,for example, organic semiconducting polymers. Those skilled in the artwill appreciate that while electroluminescent materials represent aclass of electroactive materials, a material need not beelectroluminescent to be electroactive.

As used herein, the term “organic iridium composition” is defined ascomposition comprising an iridium ion bound to at least one organicligand. For example, the chloride-bridged cyclometallated iridium dimers{(piq)₂Ir(μ-Cl)}₂ and {(ppy)₂Ir(μ-Cl)}₂ each represents an organiciridium composition comprising two iridium ions bound to thecyclometallated ligands “piq” or “ppy”. Cyclometallated ligands “piq” or“ppy” may be derived from 1-phenylisoquinoline and 2-phenylpyridinerespectively. The organic iridium compositions of the present inventioncomprise an iridium ion bound to at least one cyclometallated ligand andat least one ketopyrrole ligand. The organic iridium compositions of thepresent invention are of two types: Type (1) wherein neither of thecyclometallated ligand and the ketopyrrole ligand has a number averagemolecular weight of 2,000 grams per mole or greater (as measured by gelpermeation chromatography), and Type (2) wherein at least one of thecyclometallated ligand and the ketopyrrole ligand has a number averagemolecular weight of 2,000 grams per mole or greater (as measured by gelpermeation chromatography). Type (1) organic iridium compositions arereferred to herein as comprising “organic iridium complexes”. Type (2)organic iridium compositions are referred to herein as comprising“polymeric organic iridium complexes”.

The organic iridium compositions of both Type (1) and Type (2) are attimes referred to herein as “cyclometallated iridium complexes” becausethey comprise at least one cyclometallated ligand. A ligand is“cyclometallated” when it binds to a metal ion via a carbon-metal bondand at least one additional bond. For example, the organic iridiumcomplex {(ppy)₂Ir(BP)} comprises two cyclometallated “ppy” ligands and anon-cyclometallated ligand, “BP”, said non-cyclometallated ligand, “BP”,being derived from 2-benzoylpyrrole. The cyclometallated “ppy” ligandmay be represented as

wherein the asterisks signal the points of attachment of cyclometallatedligand to the metal via a carbon-metal bond at *1 and a nitrogen-metalbond at *2. In the example just given, the cyclometallated ligand “ppy”has formula C₁₁H₈N and is related to, but is not identical to, theneutral molecule 2-phenylpyridine which has formula C₁₁H₉N. Thoseskilled in the art will appreciate that at least in a formal sense, thecyclometallated ligand represents a carbanionic species. As noted, acyclometallated ligand is a ligand that binds to a metal ion via acarbon-metal bond and at least one additional bond. In the example justgiven *2 represents the site of the additional bond between thecyclometallated ligand and the metal ion.

In one embodiment, the present invention provides a compositioncomprising at least one organic iridium complex comprising:

(i) at least one cyclometallated ligand; and

(ii) at least one ketopyrrole ligand.

In another embodiment, the present invention provides an organic iridiumcomplex having structure I

wherein each of the ligands

is independently at each occurrence a cyclometallated ligand which maybe the some or different;R¹ is a C₃-C₄₀ aromatic radical, a C₁-C₅₀, aliphatic radical, or aC₃-C₄₀ cycloaliphatic radical;R² is independently at each occurrence a deuterium atom, a halogen, anitro group, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; and“a” is an integer from 0 to 3.

Organic iridium complexes having structure I are exemplified in Table 1.The exemplary organic iridium complexes 1a-1e in Table 1 illustrateinstances in which the ketopyrrole ligand, sometimes referred to as the“ancillary ligand”, may be derived from an alkanoyl pyrrole (See Entry1a, derived from 2-butanoylpyrrole) or a 2-benzoylpyrrole (Entries1b-1d). The exemplary organic iridium complexes 1a-1d in Table 1 furtherillustrate instances in which the cyclometallated ligands are identical.For example, in Entry 1a each of the cyclometallated ligands is derivedfrom 1-(4-bromophenyl)isoquinoline. In various embodiments of thepresent invention, however, the cyclometallated ligands need not beidentical, for example the organic iridium complex shown in Entry 1e isan organic iridium complex which comprises a cyclometallated ligandderived from 2-phenylpyridine and a cyclometallated ligand derived from4-dimethylamino-2-phenylpyridine.

TABLE 1 Exemplary Organic Iridium Complexes Having Structure I EntryKetopyrrole Ligand Structure Cyclometallated Ligand Structure 1a

1b

1c

1d

1e

Those skilled in the art will appreciate that structure I encompassesiridium complexes which are chiral. Unless expressly stated otherwise,as used herein structure I and all other structures contained in thisdisclosure which suggest an absolute stereochemistry (e.g. structureXIII) include the structure shown and its mirror image structure. Inaddition, the present invention also provides enantiomerically pure(i.e. a single enantiomer is present) organic iridium complexescomprising at least one cyclometallated ligand and at least oneketopyrrole ligand. Enantiomerically pure organic iridium complexesprovided by the present invention may be prepared from the correspondingracemic mixture by high performance liquid chromatography (hplc) using achiral stationary phase, for example. Those skilled in the art willappreciate that a wide variety of hplc columns capable of effecting theseparation a racemic mixture of an organic iridium complex into itscomponent enantiomers are commercially available, for example the CHIRALAGP column available from Chromtech Ltd. (United Kingdom). In addition,the present invention provides enantiomerically enriched organic iridiumcomplexes comprising at least one cyclometallated ligand and at leastone ketopyrrole ligand. Those skilled in the art will appreciate thatenantiomerically enriched organic iridium complexes may be prepared fromthe corresponding racemic mixture via a variety of means such as by highperformance liquid chromatography (hplc) using a chiral stationaryphase. Thus in one embodiment, the present invention provides an organiciridium complex represented by structure I which is enantiomericallypure, for example compounds 1a-1d (Table 1) possessing the absolutestereochemistry depicted in structure I. In an alternate embodiment, thepresent invention provides an organic iridium complex represented bystructure I which is enantiomerically pure, for example compounds 1a-1d(Table 1) possessing the absolute stereochemistry which is the mirrorimage of that depicted in structure I. In addition to racemic mixtures,pure enantiomers, and enantiomerically enriched compositions, thepresent invention also provides organic iridium complexes in the form ofdiastereomeric mixtures, materials which at times may present solubilityor other advantages. In addition, although structures I and XIII showthe nitrogen atoms of the cyclometallated ligands as occupyingcoordination positions having a trans-relationship, alternateconfigurations are possible. For example, the nitrogen atoms of thecyclometallated ligands of structure I,

may also occupy coordination positions having a cis-relationship.

As noted, the organic iridium complexes provided by the presentinvention comprise at least one cyclometallated ligand. The compositionsof Entries 1a-1e of Table 1 illustrate a variety of cyclometallatedligands which may be present in the organic iridium complexes of thepresent invention. In one embodiment, the cyclometallated ligand isderived from a phenylisoquinoline having structure II

wherein R³ and R⁴ are independently at each occurrence a deuterium atom,a halogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄ cycloaliphatic radical;“m” is an integer from 0 to 6; and “n” is an integer ranging from 0 to5.

The compositions of Entries 2a-2h of Table 2 illustrate a variety ofneutral isoquinolines having structure II which may serve as precursorsto the cyclometallated ligands of the organic iridium compositions ofthe present invention. For instance, Entry 2a of Table 2 represents theparent (unsubstituted) 1-phenylisoquinoline which may serve as theprecursor to the cyclometallated ligand present in certain embodimentsof the present invention. Entry 2a also shows the numbering scheme usedherein to describe phenylisoquinoline systems. Entry 2b represents theparent 3-phenylisoquinoline which may serve as the precursor to thecyclometallated ligand present in certain embodiments of the presentinvention.

TABLE 2 Phenylisoquinoline Precursors to Cyclometallated Ligands EntryR³ R⁴ m n Structure 2a — — 0 0

2b — — 0 0

2c — Me 0 1

2d CF₃ Me 1 1

2e — sec- butyl 0 1

2f iso- propyl — 1 0

2g phenyl — 1 0

2h phenyl phenyl 1 1

In one embodiment, the present invention provides an organic iridiumcomplex comprising at least one cyclometallated ligand derived from a2-phenyl pyridine compound having structure III

wherein R⁵ and R⁶ are independently at each occurrence a deuterium atom,a halogen, a nitro group, an amino group, C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical;“p” is an integer from 0 to 4: and “q” is on integer from 0 to 5.

The compositions of Entries 3a-3f of Table 3 illustrate a variety of2-phenylpyridines III which may serve as precursors to thecyclometallated ligands of the organic iridium compositions of thepresent invention. The composition of Entry 3a illustrates the parent2-phenylpyridine and the numbering scheme used to describephenylpyridines. The composition of Entry 3b illustrates2,6-diphenylpyridine. The composition of Entry 3e illustrates apolysubstituted 2-phenylpyridine in which with reference to genericstructure III, R⁵ is a trifluoromethyl group, “p” is 1, and R⁶ isindependently a bromine group and a methyl group and “q” is 2. Thecomposition of Entry 3f illustrates an embodiment in which R⁵ isindependently a chlorine group and a methyl group, and “p” is 2. Thecomposition of Entry 3f further illustrates an embodiment in which R⁶ isa divalent C₁ aliphatic radical, —OC₁H₂O—, which is attached at the 3′-and 4′-positions of the phenyl ring.

TABLE 3 2-Phenylpyridine Precursors to Cyclometallated Ligands Entry R⁵R⁶ p q Structure 3a — — 0 0

3b Ph — 1 0

3c Me₂N— — 1 0

3d — Me 0 1

3e CF₃ Br, Me 1 2

3f Cl, Me OC₁H₂O 2 1

In one embodiment, the present invention provides an organic iridiumcomplex comprising at least one cyclometallated ligand derived from astyryl-isoquinoline compound having structure IV

wherein R⁷ and R⁸ are independently at each occurrence a deuterium atom,a halogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical;“d” is an integer from 0 to 6; and “e” is an integer from 0 to 5.

The composition of Entry 4a illustrates the parent 1-styrylisoquinolineand the numbering system used to describe styrylisoquinolines generally.The composition of Entry 4b illustrates 3-styrylisoquinoline. Thecompositions of Entries 4c and 4d illustrate a substituted3-styrylisoquinoline and a substituted 1-styrylisoquinolinerespectively.

TABLE 4 Styrylisoquinoline Precursors to Cyclometallated Ligands EntryR⁷ R⁸ d e Structure 4a — — 0 0

4b — — 0 0

4c — CF₃ 0 1

4d Cl Et 1 1

From the foregoing discussion it will be understood by those skilled inthe art that in one embodiment, the cyclometallated ligand may bederived from a 1-phenylisoquinoline derivative (e.g.1-phenylisoquinoline), a 3-phenylisoquinoline derivative (e.g.3-phenylisoquinoline), a 2-phenylpyridine derivative (e.g.2-phenylpyridine), 1-styrylisoquinoline derivative (e.g.1-styrylisoquinoline), a 3-styrylisoquinoline derivative (e.g.3-styrylisoquinoline), or a combination thereof. In the present contextthe phrase “or a combination thereof” means that two or morecyclometallated ligands are derived from two or more of the enumeratedprecursors; a 1-phenylisoquinoline, a 3-phenylisoquinoline, a2-phenylpyridine, a 1-styrylisoquinoline, and a 3-styrylisoquinoline.Generally, as used herein, when it follows an enumerated group ofchoices, the phrase “or a combination thereof” means that that two ormore of the choices may be combined in an embodiment.

It will be apparent to those skilled in the art that a wide variety ofadditional precursors to cyclometallated ligands are possible, forexample 2-phenylquinoline, 2-styrylpyridine; 2-phenyl-4,4′-bipyridine;2-(2′-thienyl)pyridine; and like compositions which juxtapose achelating nitrogen atom with a C—H bond susceptible to metallation in amanner analogous to that observed in systems like 1-phenylisoquinoline,2-phenylpyridine, 1-styrylpyridine, and 3-styrylisoquinoline. Additionalprecursors to cyclometallated ligands are illustrated in Table 5.

TABLE 5 Additional Examples of Neutral Precursors to CyclometallatedLigands

Among the precursors to cyclometallated ligands presented in Table 5above, Entry 5f (coumarin 6, CAS No. 38215-36-0), is a highlyfluorescent compound displaying a fluorescence maximum at about 500nanometers (nm) in ethanol solution at an excitation wavelength of 420(nm) with a quantum yield of about 0.78. In one embodiment, the presentinvention provides an organic iridium composition comprising at leastone ketopyrrole ligand and at least one cyclometallated ligand derivedfrom coumarin 6.

Precursors from which the cyclometallated ligands may be derived are inmany instances available commercially. Alternately, cyclometallatedligand precursors may be prepared by methods known to those skilled inthe art. For, example, 1-phenylisoquinoline may be made by reacting1,1-diphenyl methylamine and 2,2-diethoxy acetaldehyde in the presenceof an acid catalyst, as shown in Scheme 1.

The cyclometallated ligand precursor 3-phenylisoquinoline may beprepared via an acid catalyzed reaction between benzaldehyde and1-phenyl-2,2-diethoxy ethyl amine, as shown in Scheme 2.

Those skilled in the art will understand that the transformationsdepicted in Schemes 1 and 2 may be applied to the preparation of a widevariety of substituted 1-phenylisoquinolines and 3-phenylisoquinolines,and additional synthetic routs to cyclometallated ligand precursors arereadily available in the chemical literature.

Alternate methods for the preparation of cyclometallated ligandprecursors include reaction of a bromoisoquinoline with a phenyl boronicacid using the well known Suzuki coupling methodology. Phenylpyridinesmay be prepared analogously. Other methods known to those skilled in theart include the Bischler-Napieralski reaction, Pictet-Gams isoquinolinesynthesis, and the like.

Numerous 2-phenylpyridine derivatives III which may serve as precursorsto the cyclometallated ligands of the organic iridium compositions ofthe present invention are commercially available or may be synthesizedfollowing standard synthetic procedures known to those skilled in theart.

Similarly, numerous styrylisoquinoline derivatives IV which may serve asthe precursors to the cyclometallated ligands of the organic iridiumcompositions of the present invention are commercially available or maybe synthesized following standard synthetic procedures known to thoseskilled in the art.

In one embodiment, the present invention provides an organic iridiumcomplex comprising at least one cyclometallated ligand; and at least oneketopyrrole ligand, wherein the ketopyrrole ligand is derived from aketopyrrole having structure V

wherein R¹ is a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, ora C₃-C₄₀ cycloaliphatic radical;R² is independently at each occurrence a deuterium atom, a halogen, anitro group, on amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; and“a” is an integer from 0 to 3.

The compositions of Entries 6a-6d of Table 6 illustrate a variety ofketopyrroles from which the ketopyrrole ligand of the organic iridiumcompositions of the present invention may be derived. For example, thecomposition of Entry 6a illustrates 2-acetylpyrrole. The composition ofEntry 6b illustrates 2-pivaloylpyrrole. The composition of Entry 6c,2-cyclohexanoyl-5-methylpyrrole, illustrates a ketopyrrole in which R¹is cyclohexyl and R² is methyl, and “a” is 1. The composition of Entry6d, 2-cyclopropanoyl-3-chloro-5-methylpyrrole, illustrates a ketopyrrolein which R¹ is cyclopropyl, and R² is independently chloro and methyl,and “a” is 2. Those skilled in the art will appreciate that theindividual species presented in Table 6 are illustrative only, and thatmany additional ketopyrrole structures are possible, and that in lightof the teachings herein, these additional ketopyrroles would be usefulin the preparation of the organic iridium complexes provided by thepresent invention.

TABLE 6 Ketopyrrole Precursors to Ketopyrrole Ligands Entry R¹ R² aStructure 6a CH₃ — 0

6b t-Bu — 0

6c Cyclo- hexyl CH₃ 1

6d Cyclo- propyl Cl, CH₃ 2

In another embodiment, the present invention provides an organic iridiumcomplex comprising at least one cyclometallated ligand; and at least oneketopyrrole ligand, wherein the ketopyrrole ligand is derived from abenzoylpyrrole having structure VI

wherein R² and R⁹ are independently at each occurrence a deuterium atom,a halogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical;“a” is an integer from 0 to 3; and “s” is an integer from 0 to 5.

The compositions of Entries 7a-7f of Table 7 illustrate a variety ofbenzoylpyrroles from which the ketopyrrole ligand of the organic iridiumcompositions of the present invention may be derived. The composition ofEntry 7a illustrates the parent (unsubstituted) 2-benzoylpyrrole (Seealso Table 1, Entry 1b) and the numbering scheme used forbenzoylpyrroles generally. The composition of Entry 7b illustrates a2-(4-bromobenzoyl)pyrrole wherein “a” is 0, “s” is 1 and R⁹ is bromo.The composition of Entry 7c illustrates a2-(3,5-dibromobenzoyl)-4-tert-butypyrrole wherein R² is tert-butyl, “a”is 1, R⁹ is bromo, and “s” is 2. The composition of Entry 7d,2-(3-phenylbenzoyl)pyrrole, illustrates a benzoylpyrrole in which “a” is0, R⁹ is phenyl and “s” is 1. In certain instances, the benzoylpyrrolesthemselves represent novel chemical structures, for example thecompositions of Entries 7e and 7f. Benzoylpyrroles 7e and 7f are usefulin the preparation of the organic iridium complexes of the presentinvention as is demonstrated herein. Those skilled in the art willappreciate that the individual species presented in Table 7 areillustrative only, and that many additional ketopyrrole structures arepossible, and that in light of the teachings herein, these additionalketopyrroles would be useful in the preparation of the organic iridiumcomplexes provided by the present invention.

TABLE 7 Benzoylpyrrole Precursors to Ketopyrrole Ligands Entry R² R⁹ a sStructure 7a — — 0 0

7b — Br 0 1

7c t-Bu Br, Br 1 2

7d — Ph 0 1

7e — Br, Br 0 2

7f — OH, OH 0 2

Ketopyrroles, for example 2-benzoylpyrrole, may be synthesized bymethods known to those skilled in the art. A common method ofpreparation includes electrophilic addition of a suitable carbonylreagent to a pyrrole ring. For example, benzoylpyrrole may be preparedby Vilsmeier-Hack aroylation of pyrrole with N,N-diethylbenzamide (SeeExamples section herein). The Examples section of this disclosureprovides detailed guidance on the preparation of a wide variety ofketopyrroles which may be used to make the organic iridium compositionsof the present invention.

In one embodiment, the organic iridium complexes of the presentinvention may be prepared using the ligand precursors discussed hereinas follows. First, a cyclometallated ligand precursor such as1-phenylisoquinoline is heated with iridium (III) chloride (IrCl₃) inthe presence of a solvent such as aqueous 2-methoxyethanol, to affordthe chloride-bridged cyclometallated iridium dimer intermediate (e.g.{(piq)₂Ir(μ-Cl)}₂). The chloride-bridged cyclometallated iridium dimerintermediate may be reacted with a ketopyrrole in the presence of a baseto afford the corresponding organic iridium complex comprising twocyclometallated ligands and an ancillary ligand derived from aketopyrrole (a ketopyrrolic ligand).

In one embodiment, the present invention provides an organic iridiumcomplex having structure VII

wherein R², R³, R⁴, R⁹ are independently at each occurrence a deuteriumatom, a halogen, a nitro group, an amino group, a C₃-C₄₀ aromaticradical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ radical;“a” is an integer from 0 to 3: “m” is an integer from 0 to 6: “n” is aninteger from 0 to 4; and “s” is an integer from 0 to 5.

Exemplary organic iridium complexes having structure VII are provided inTable 8. The composition of Entry 8a illustrates an organic iridiumcomplex of the present invention wherein the ketopyrrole ligandcomprises a trifluoromethyl group (“a”=0, R⁹=CF₃, “s”=1) and thecyclometallated ligands are derived from 1-phenylisoquinoline (“m”=0,“n”=0). The composition of Entry 8b illustrates an organic iridiumcomplex of the present invention wherein the ketopyrrole ligandcomprises a methyl group and a trifluoromethyl group (R²=CH₃“a”=1,R⁹=CF₃, “s”=1) and the cyclometallated ligands are derived from7-hydroxy-1-phenylisoquinoline (R³=OH, “m”=1, “n”=0). The composition ofEntry 8c illustrates an organic iridium complex of the present inventionwherein the ketopyrrole ligand comprises a methyl group and a divalent—O(CH₂)O-radical (R²=CH₃“a”=1, R⁹=—O(CH₂)O—, “s”=1) and thecyclometallated ligands are derived from7-dimethylamino-1-phenylisoquinoline (R³═NMe₂, “m”=1, “n”=0). Thecomposition of Entry 8d illustrates an organic iridium complex of thepresent invention wherein the ketopyrrole ligand comprises a nonyloxygroup (“a”=0, R⁹=CH₃(CH₂)₈—O—, “s”=1) and the cyclometallated ligandsare derived from 1-phenylisoquinoline (“m”=0, “n”=0). The composition ofEntry 8e illustrates an organic iridium complex of the present inventionwherein the ketopyrrole ligand comprises two bromine groups (“a”=0,R⁹=Br, “s”=2) at the 3- and 5-positions of the benzoyl moiety, and thecyclometallated ligands are derived from the7-nonyloxy-1-phenylisoquinoline (R³=CH₃(CH₂)₈—O—, “m”=1, “n”=0).Finally, the composition of Entry 8f illustrates an organic iridiumcomplex of the present invention wherein the ketopyrrole ligandcomprises two hydroxy groups (“a”=0, R⁹=OH, “s”=2) at the 3- and5-positions of the benzoyl moiety, and the cyclometallated ligands arederived from 7-nonyloxy-1-(3′-trifluoromethylphenyl)isoquinoline(R³=CH₃(CH₂)₈—O—, “m”=1, R⁴=CF₃, “n”=1).

TABLE 8 Exemplary Organic Iridium Complexes VII Entry Ketopyrrole LigandStructure Cyclometallated Ligand Structure 8a

8b

8c

8d

8e

8f

In one embodiment, the present invention provides an organic iridiumcomplex having structure VIII.

Exemplary organic iridium complexes of the present invention havingstructure VIII are provided in Table 9. The composition of Entry 9aillustrates an organic iridium complex of the present invention which isa racemic mixture comprising equal amounts of the two enantiomers shown,Enantiomer A, and Enantiomer B. Those skilled in the art will appreciatethat Enantiomer A represents the mirror image of Enantiomer B,Enantiomer B represents the mirror image of Enantiomer A, and eachenantiomer has C₁ symmetry. The composition of Entry 9b illustrates anorganic iridium complex of the present invention which is a singleenantiomer (Enantiomer A). The composition of Entry 9c illustrates anorganic iridium complex of the present invention which is a singleenantiomer (Enantiomer B) which is the mirror image of Enantiomer A. Asnoted, the present invention also provides organic iridium complexeswhich are not enantiomerically pure (i.e. do not consist of a singleenantiomer) but which are enantiomerically enriched, for example anenantiomerically enriched organic iridium complex composition comprising90 percent by weight Enantiomer A (Table 9) and 10 percent by weightEnantiomer B. (Table 9). The composition of Entry 9d illustrates anorganic iridium complex of the present invention wherein one of thecoordinating nitrogens of the cyclometallated ligand (those nitrogensmarked †) are in a cis-relationship (as opposed to a trans-relationshipfeatured in Enantiomers A and Enantiomer B) which is a racemic mixture.The non-tapered bold lines shown in the structure depicted in Entry 9ddo not depict absolute stereochemistry.

TABLE 9 Exemplary Organic Iridium Complexes VIII Entry Structure 9a

Enantiomer A Enantiomer B 9b Single Enantiomer A 9c Single Enantiomer B9d

cis (racemic)

In yet another embodiment, the present invention provides organiciridium complexes having structure IX

wherein R², R⁵, R⁶, and R⁹ are independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical;“a” is an integer from 0 to 3; “p” is an integer from 0 to 4; “q” is aninteger from 0 to 4; and “s” is an integer from 0 to 5.

Exemplary organic iridium complexes having structure IX are provided inTable 10. The composition of Entry 10a illustrates an organic iridiumcomplex of the present invention wherein the ketopyrrole ligand isunsubstituted (“a”=0, “s”=0) and the cyclometallated ligands are derivedfrom 2-phenyl-5-trifluoromethylpyridine (R⁵=CF₃, “p”=1, “q”=0). Thecomposition of Entry 10b illustrates an organic iridium complex of thepresent invention wherein the ketopyrrole ligand comprises a3,5-dihydroxybenzoyl moiety (“a”=0, R⁹=OH, “s”=2) and thecyclometallated ligands are derived from2-phenyl-5-trifluoromethylpyridine (R⁵=CF₃, “p”=1, “q”=0). Thecomposition of Entry 10c illustrates an organic iridium complex of thepresent invention wherein the ketopyrrole ligand comprises amethylacryloyloxy group and (“a”=0, R⁹=methacryloyloxy, “s”=1) and thecyclometallated ligands are derived from2-(3-dimethylaminophenyl)pyridine (“p”=0, R=NMe₂, “q”=1). Thecomposition of Entry 10d illustrates an organic iridium complex of thepresent invention wherein the ketopyrrole ligand comprises a1,1-dimethyl-1-butyl group and a chloroformate group (“a”=1,R²=(CH₃)₂(CH₃CH₂CH₂)C—, R⁹=ClCOO—, “s”=1) and the cyclometallatedligands are unsubstituted (“p”=0, “q”=0). The composition of Entry 10eillustrates an organic iridium complex of the present invention whereinthe ketopyrrole ligand comprises a 4-phenylbenzoyl moiety (“a”=0,R⁹=phenyl, “s”=1).

TABLE 10 Exemplary Organic Iridium Complexes Having Structure IX EntryStructure 10a

10b

10c

10d

10e

In one embodiment, the present invention provides an organic iridiumcomplex having structure X.

In yet another embodiment, the present invention provides organiciridium complexes having structure XI

wherein R², R⁷, R⁸, and R⁹ are independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical;“a” is an integer from 0 to 3; “d” is on integer from 0 to 6: “e” is aninteger from 0 to 5; and “s” is an integer from 0 to 5.

Exemplary organic iridium complexes having structure XI are provided inTable 11. The composition of Entry 11a illustrates an organic iridiumcomplex of the present invention wherein the ketopyrrole ligand isunsubstituted (“a”=0, “s”=0) and the cyclometallated ligands are derivedfrom 1-(3′,5′-dibromostyryl)isoquinoline (“d”=0, R⁸=Br, “e”=2). Thecomposition of Entry 11b illustrates an organic iridium complex of thepresent invention wherein the cyclometallated ligands are derived from1-(3′,5′-dibromostyryl)-7-t-butyldimethylsilyloxyisoquinoline(R⁷=t-butyldimethylsilyloxy, “d”=1, R⁸=Br, “e”=2). The composition ofEntry 11c illustrates an organic iridium complex of the presentinvention wherein the ketopyrrole ligand comprises at-butyldimethylsilyloxybenzoyl moiety and (“a”=0,R⁹=t-butyldimethylsilyloxy, “s”=1) and the cyclometallated ligands arederived from 1-styryl-7-t-butyldimethylsilyloxyisoquinoline(R⁷=t-butyldimethylsilyloxy, “d”=1, “e”=0). The composition of Entry 11dillustrates an organic iridium complex of the present invention whereinthe ketopyrrole ligand comprises a 4-n-hexanoyloxybenzoyl moiety (“a”=0,R⁹=—OCO(CH₂)₄CH₃, “s”=1) and the cyclometallated ligands are derivedfrom 1-styryl-7-bromoisoquinoline (R⁷=Br, “d”=1, “e”=0). The compositionof Entry 1e illustrates an organic iridium complex of the presentinvention wherein the ketopyrrole ligand comprises a 4-vinylbenzoylmoiety (“a”=0, R⁹=vinyl, “s”=1) and the cyclometallated ligands arederived from 1-styrylisoquinoline (“d”=0, “e”=0).

TABLE 11 Exemplary Organic Iridium Complexes XI Entry Structure 11a

11b

11c

11d

11e

In one embodiment, the present invention provides an organic iridiumcomplex having structure XII.

In one embodiment, the present invention provides a compositioncomprising at least one organic iridium complex having structure XIII

wherein each of the ligands

is independently at each occurrence a cyclometallated ligand which maybe the some or different;Ar¹ is a C₃-C₅₀ aromatic radical;R² is independently at each occurrence a deuterium atom, a halogen, anitro group, on amino group, a C₄-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical;“a” is an integer from 0 to 3.

Those skilled in the art will appreciate that structure XIII representsa subgenus of structure I wherein the group R¹ is a C₃-C₄₀ aromaticradical. Exemplary organic iridium complexes having structure XIII areprovided in Table 12.

The exemplary organic iridium complexes 12a-12e in Table 12 illustrateinstances in which the ketopyrrole ligand, may be derived from an aroylpyrrole (See Entry 12a, derived from 2-(2-thienylcarbonyl)pyrrole (CASNo. 13169-77-2). The exemplary organic iridium complexes 12a-12e inTable 12 further illustrate instances in which the cyclometallatedligands are identical. For example, in Entry 12a each of thecyclometallated ligands is derived from1-(3′-methoxyphenyl)isoquinoline. The exemplary organic iridium complexof Entry 12b comprises a ketopyrrole ligand derived from2-(2,5-dimethyl-3-thienylcarbonyl)pyrrole wherein Ar¹ is a C₆ aromaticradical. The iridium complex of Entry 12d comprises a ketopyrrole ligandwhich may be derived from 2-(3,5-dimethacroyloxybenzoyl)pyrrole whereinAr¹ is a C₁₄ aromatic radical. The organic iridium complex of Entry 12ecomprises a ketopyrrole ligand which may be derived from2-(1-azulenylcarbonyl)pyrrole wherein Ar¹ is a C₁₀ aromatic radical.Synthetic methodologies useful for the preparation of the ketopyrroleprecursors which may be used to prepare the organic iridium complexes12a-12e are known to those skilled in the art. Similarly, syntheticmethodologies useful for the preparation of the cyclometallated ligandprecursors which may be used to prepare organic iridium complexes12a-12e are likewise known to those skilled in the art.

TABLE 12 Exemplary Organic Iridium Complexes Having Structure XIII EntryKetopyrrole Ligand Structure Cyclometallated Ligand Structure 12a

12b

12c

12d

12e

In one embodiment, the present invention provides an organic iridiumcomplex having structure XIV.

As illustrated in the case of organic iridium complexes VII, the organiciridium compositions provided by the present invention may, in variousembodiments, be a single enantiomer, a racemic mixture, a mixture ofdiastereomers, or an enantiomerically enriched composition. Thus in oneembodiment, the present invention provides organic iridium complex XIVas an enantiomerically enriched composition.

In one aspect the present invention provides organic iridiumcompositions which are deuterated. A compound is deuterated when itcomprises deuterium in an amount which exceeds the natural abundancelevel of deuterium ordinarily anticipated. For example, the naturalabundance level of deuterium in an organic iridium complex such ascompound VIII would be such that about 0.015% of the sites in compoundVIII nominally occupied by hydrogen would in fact be occupied bydeuterium. (Compound VIII comprises 28 sites nominally occupied byhydrogen, the default substituent.) Deuterated organic iridium complexesmay be prepared from deuterated cyclometallated ligand precursors and/ordeuterated ketopyrrole ligand precursors. In certain embodiments,deuterated organic iridium complexes display enhanced quantumefficiencies relative to the corresponding material containing deuteriumat natural abundance deuterium levels (i.e. about 0.015%).

Thus, in one embodiment, the present invention provides a deuteratedorganic iridium complex comprising at least one cyclometallated ligandand at least one ketopyrrole ligand. In one embodiment, the organiciridium complex is at least 10 percent deuterated. In anotherembodiment, the organic iridium complex is at least 40 percentdeuterated. In an alternate embodiment, the organic iridium complex isat least 60 percent deuterated. In yet another embodiment, the organiciridium complex is at least 80 percent deuterated.

In a further embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex. Anelectrophosphorescent composition is a composition which emits light byradiative decay of a triplet excited state formed as a result of theapplication of a voltage bias. In one embodiment, the present inventionprovides an electrophosphorescent composition which when subjected to avoltage bias, emits light primarily from a triplet excited state of anorganic iridium complex formed by energy transfer from the host materialto the organic iridium complex. The organic iridium complexes providedby the present invention are well suited for use inelectrophosphorescent compositions because energy transfer from theexcited state of the host material to the organic iridium complex is inmany instances exceedingly efficient. Suitable electroactive hostmaterials include electroluminescent materials and otherwiseelectroactive materials. Suitable non-polymeric host materials areexemplified in Table 13 together with their Chemical Abstracts RegistryNumber (CAS No.).

TABLE 13 Exemplary Non-Polymeric Host Materials

CAS No. 120-12-7

CAS No. 58328-31-7

CAS No. 2085-33-8

CAS No. 150405-69-9

CAS No. 145024-29-9

CAS No. 189363-47-1

CAS No. 139092-78-7

CAS No. 1662-01-7

In an alternate embodiment, the host material is an electroactivepolymeric material. Suitable electroactive polymeric materials includepolyvinylcarbazole (PVK), polyphenylenevinylene (PPV),phenyl-substituted polyphenylenevinylene (PhPPV), poly(9,9-dioctylfluorene), and the like.

Thus, in one embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex having structureI. In an alternate embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex having structureVII. In yet another embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex having structureIX. In yet still another embodiment, the present invention provides anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex having structureXI.

In one embodiment, the electrophosphorescent composition comprises ahost material which is a blue light emitting electroluminescent organicmaterial, for example, poly(9,9-dioctyl fluorene).

In one embodiment, the organic iridium complex is characterized by alowest accessible triplet state energy T1 and the electroactive hostmaterial is characterized by a lowest accessible triplet state energyT2. As will be appreciated by those skilled in the art, energy transferfrom the electroactive host material to the organic iridium complex canbe especially favorable under circumstances wherein T1 is less than T2.Thus, in one embodiment, the electrophosphorescent composition comprisesa blue light emitting electroluminescent material and an organic iridiumcomplex, wherein the organic iridium complex is characterized by alowest accessible triplet state energy T1 and the blue light emittingelectroluminescent organic material is characterized by a lowestaccessible triplet state energy T2, and wherein T1 is less than T2.

In one embodiment, the present invention provides anelectrophosphorescent composition comprising an electroactive hostmaterial and an organic iridium complex comprising at least onecyclometallated ligand and at least one ketopyrrole ligand, wherein theorganic iridium complex is present in an amount corresponding to fromabout 0.01 percent to about 50 percent by weight of the entire weight ofthe electrophosphorescent composition. In another embodiment, theorganic iridium complex is present in an amount corresponding to fromabout 0.1 percent to about 10 percent by weight of the entire weight ofthe electrophosphorescent composition. In yet another embodiment anotherembodiment, the organic iridium complex is present in an amountcorresponding to from about 0.5 percent to about 5 percent by weight ofthe entire weight of the electrophosphorescent composition.

Exemplary electrophosphorescent compositions comprising at least oneelectroactive host material and at least one organic iridium complex aregiven in Table 14. For example, the composition of Entry 14a is anelectrophosphorescent composition suitable for use in an electronicdevice such as an OLED, said electrophosphorescent compositioncontaining 4 percent by weight organic iridium complex VIII and 96% byweight of carbazole derivative TCTA. The composition of Entry 14d is anelectrophosphorescent composition suitable for use in an electronicdevice, said electrophosphorescent composition containing 5 percent byweight organic iridium complex XIV, 40 percent by weight of triazolederivative TAZ, 40 percent by weight of dicarbazole derivative CBP, and15 percent by weight of bis(triarylamine) BTA.

TABLE 14 Electroactive Host-Organic iridium complex Compositions HostOrganic iridium Material Component 3 Component 4 Entry complex (wt %*)(wt %*) (wt %*) (wt %*) 14a VIII (4%) TCTA (96%) — (0%) — (0%) 14b X(5%) BTA (95%) — (0%) — (0%) 14c XIV (50%) Alq₃ (50%) — (0%) — (0%) 14dXIV (5%) TAZ (40%) CBP (40%) BTA (15%) 14e XII (10%) CBP (90%) — (0%) —(0%) 14f XII (5%) Anthracene Bphen (15%) — (0%) (80%) *“Wt %” refers tothe weight percentage of a component relative to the entire weight ofthe electroactive host-organic iridium complex composition as a whole.

In one embodiment, the present invention provides a polymer compositioncomprising (1) a polymeric component, and (2) at least one organiciridium complex, the at least one organic iridium complex comprising atleast one cyclometallated ligand and at least one ketopyrrole ligand.The polymeric component comprises at least one polymeric material havinga number average molecular weight (M_(n)) greater than 2,000 grams permole as determined by gel permeation chromatography. The polymericcomponent is not an organic iridium complex having an overall numberaverage molecular weight greater than 2,000 grams per mole. Nor is thepolymeric component a polymeric organic iridium complex comprising atleast one ligand having a number average molecular weight of greaterthan 2,000 grams per mole. Those skilled in the art will appreciate thatnumber average molecular weight of polymeric materials may also bedetermined by other techniques such as ¹H-NMR spectroscopy. In oneembodiment, the polymeric component comprises at least one polymericmaterial having a number average molecular weight (M_(n)) greater thanabout 5,000 grams per mole as determined by gel permeationchromatography. In another embodiment, the polymeric component comprisesat least one polymeric material having a number average molecular weight(M_(n)) greater than about 15,000 grams per mole as determined by gelpermeation chromatography. In yet another embodiment, the polymericcomponent comprises at least one polymeric material having a numberaverage molecular weight (M_(n)) greater than about 25,000 grams permole as determined by gel permeation chromatography.

The polymeric component may be, for example, a bisphenol Apolycarbonate, a polymer blend comprising a bisphenol A polycarbonate, abisphenol A copolycarbonate, a blend comprising a bisphenol Acopolycarbonate, or like polymeric materials. Other suitable polymersinclude vinyl polymers such as polyvinyl chloride, polystyrene,poly(methyl methacrylate), poly(methyl acrylate), polymerizedpolyacrylates such as Sartomer 454, and the like; acetal polymers;polyesters such as poly(ethylene terephthalate); polyamides such asnylon 6; polyimides; polyetherimides such as ULTEM;polyethertherketones; polysulfones; polyethersulfones such as RADEL andUDEL, and the like. The polymeric component may be homopolymer, a randomcopolymer, a block copolymer, a terpolymer, a graft-copolymer, analternating copolymer, or like polymeric material. Polymeric blendsuseful as the polymeric component may be prepared using standardtechniques known in the art, for example extrusion blending.

In one embodiment, the polymeric component comprises an electroactivepolymer. Electroactive polymers are polymers which are susceptible tocharge conduction when subjected to a voltage bias, for examplepolymeric materials which conduct electrons and or holes in an organiclight emitting device (OLED). Electroactive polymers include, forexample, organic semiconducting polymers. Those skilled in the art willappreciate that while electroluminescent polymers represent a class ofelectroactive polymers, a material need not be electroluminescent to beelectroactive. Electroactive polymers generally possess a delocalizedπ-electron system, which typically enables the polymer chains to supportpositive charge carriers (holes) and negative charge carriers(electrons) with relatively high mobility. Suitable electroactivepolymers are illustrated by poly(n-vinylcarbazole) (“PVK”, emittingviolet-to-blue light in a wavelength range of from about 380 to about500 nanometers) and poly(n-vinylcarbazole) derivatives; polyfluorene andpolyfluorene derivatives such as poly(dialkyl fluorene), for examplepoly(9,9-dihexyl fluorene) (emitting light in a wavelength range of fromabout 410 to about 550 nanometers), poly(dioctyl fluorene) (wavelengthat peak electroluminescent (EL) emission of about 436 nanometers), andpoly{9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl} (emitting light in awavelength range of from about 410 to about 550 nanometers);poly(paraphenylene) (“PPP”) and its derivatives such aspoly(2-decyloxy-1,4-phenylene) (emitting light in a wavelength range offrom about 400 to about 550 nanometers) andpoly(2,5-diheptyl-1,4-phenylene); poly(p-phenylene vinylene) (“PPV”) andits derivatives such as dialkoxy-substituted PPV and cyano-substitutedPPV; polythiophene and its derivatives such as poly(3-alkylthiophene),poly(4,4′-dialkyl-2,2′-bithiophene), and poly(2,5-thienylene vinylene);poly(pyridine vinylene) and its derivatives; polyquinoxaline and itsderivatives; and polyquinoline and its derivatives. Mixtures of thesepolymers and/or copolymers comprising structural units common to two ormore of the aforementioned polymers may be used as the polymericcomponent.

Additionally, polysilanes may in some circumstances be suitableelectroactive polymers which may serve as the polymeric component invarious aspects of the present invention. Typically, polysilanes arelinear silicon-backbone polymers substituted with a variety of alkyland/or aryl groups. Polysilanes are quasi one-dimensional materials withdelocalized sigma-conjugated electrons along polymer backbone. Examplesof suitable polysilanes include, but are not limited to,poly(di-n-butylsilane), poly(di-n-pentylsilane), poly(di-n-hexylsilane),poly(methylphenylsilane), and poly{bis(p-butylphenyl)silane}. Thepolysilanes generally emit light in a wavelength in a range from about320 nanometers to about 420 nanometers.

In one embodiment, the present invention provides a polymer compositioncomprising a poly(dialkyl fluorene) polymeric component and an organiciridium complex comprising at least one cyclometallated ligand and atleast one ketopyrrole ligand.

Thus, in one aspect, the present invention provides a polymercomposition which is a light emitting polymer composition, said lightemitting polymer composition comprising an electroluminescent polymerand at least one organic iridium complex, said organic iridium complexcomprising at least one cyclometallated ligand and at least oneketopyrrole ligand. In one embodiment, the light emitting polymercomposition comprises an electroluminescent polymer selected from thegroup consisting of poly(n-vinylcarbazole) (PVK), poly(n-vinylcarbazole)derivatives, poly(dialkyl fluorene), poly(9,9-dihexyl fluorene),poly(9,9-dioctyl fluorene),poly{9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl}, poly(paraphenylene)(“PPP”), poly(2-decyloxy-1,4-phenylene),poly(2,5-diheptyl-1,4-phenylene), poly(p-phenylene vinylene) (“PPV”),and mixtures thereof.

As noted, in one aspect the present invention provides a polymercomposition comprising a polymeric component and an organic iridiumcomplex. The organic iridium complex can be any one of the variousorganic iridium complexes of the present invention comprising at leastone cyclometallated ligand and at least one ketopyrrole ligand. Inaddition, the polymer composition provided by the present invention maycomprise more than one organic iridium complex. In one embodiment, thepolymer composition provided by the present invention comprises at leasttwo different organic iridium complexes. In an alternate embodiment, thepresent invention provides a polymer composition comprising a pluralityof organic iridium complexes.

As noted, the organic iridium complex can be any one of the variouscyclometallated iridium complexes discussed herein comprising at leastone cyclometallated ligand and at least one ketopyrrole ligand. Forexample, in one embodiment, the present invention provides a polymercomposition comprising a polymeric component and an organic iridiumcomplex having structure I, and in another embodiment the presentinvention provides a polymer composition comprising a polymericcomponent and an organic iridium complex wherein the cyclometallatedligand is derived from a phenylisoquinoline having structure II. Inanother embodiment, at least one component of the polymer composition isdeuterated. In one embodiment, the organic iridium complex isdeuterated. In an alternate embodiment, the polymeric component isdeuterated.

In one aspect, the present invention provides a polymer compositioncomprising an electroluminescent polymer and an organic iridium complexsaid organic iridium complex comprising at least one cyclometallatedligand and at least one ketopyrrole ligand, wherein the organic iridiumcomplex is characterized by a lowest accessible triplet state energy T1,and the electroluminescent polymer is characterized by a lowestaccessible triplet state energy T2, and wherein T1 is less than T2. Asnoted earlier, energy transfer from the electroluminescent polymer tothe organic iridium complex can be especially favorable undercircumstances wherein T1 is less than T2. In one embodiment, theelectroluminescent polymer is a blue light emitting electroluminescentpolymer characterized by a lowest accessible triplet state energy T2,wherein T2 is greater than the lowest accessible triplet state energy,T1, of the organic iridium complex.

Polymer compositions comprising a polymeric component and at least oneorganic iridium complex can be prepared using conventional melt blendingtechniques, such as dispersing the organic iridium complex into apolymer melt. Alternately, the polymer composition may be prepared bymixing a solution of the polymer with a solution of the organic iridiumcomplex and evaporating the solvent to prepare, for example, the polymercomposition in the form of a film. In yet another embodiment, thepolymer composition may be prepared by dispersing the organic iridiumcomplex in a monomer such as a mixture of methyl methacrylate andSartomer 454 and subsequently polymerizing the monomer mixture in thepresence of the organic iridium complex. The Examples section of thisdisclosure provides additional guidance on the preparation of polymercompositions provided by the present invention.

Exemplary compositions comprising a polymeric component and an organiciridium complex comprising at least one cyclometallated ligand and atleast one ketopyrrole ligand are given in Table 15. The composition ofEntry 15a is a polymer composition comprising a bisphenol Apolycarbonate and organic iridium complex VIII in an amountcorresponding to 3 weight percent of the total weight of the polymercomposition. The polymer composition of Entry 15b comprises polystyreneand organic iridium complex VIII in an amount corresponding to 5 weightpercent of the total weight of the polymer composition. The compositionsof Entries 15e and 15f comprise respectively poly(n-vinylcarbazole) andODX-7 (CAS No. 138372-67-5) and poly(N-vinylcarbazole) and PBD (CAS No.15082-28-7) respectively. The composition of Entry 15g comprisespoly(9,9-dioctyl fluorene) as an electroactive polymeric component, andorganic iridium complex XII.

TABLE 15 Exemplary Polymer Compositions Of The Invention Organic iridiumcomplex Polymeric Component Entry (wt %*) Polymer Type (wt %*) M_(n) 15aVIII (3%) Bisphenol A polycarbonate (97%) 12,000 15b VIII (5%)polystyrene (95%) 225,000 15c VIII (5%) PMMA (95%) 15,000 15d XIV (5%)poly(ethylene terephthalate) (95%) 22,500 15e XII (3%)poly(n-vinylcarbazole) (90%), ODX- 17,000 7 (7%) 15f XII (3%)poly(n-vinylcarbazole) (90%), PBD 17,000 (7%) 15g XII (5%)poly(9,9-dioctyl fluorene) (98%) 8,500 *Weight percentage based on thetotal weight of the composition

In another aspect, the present invention provides a compositioncomprising a polymeric organic iridium complex, said polymeric organiciridium complex comprising at least one cyclometallated ligand and atleast one ketopyrrole ligand, wherein at least one of saidcyclometallated ligand or said ketopyrrole ligand is a polymeric ligand.As noted, an organic iridium composition of the present invention is apolymeric organic iridium complex when it comprises at least onecyclometallated ligand and at least one ketopyrrole ligand wherein atleast one ligand of the composition has a number average molecularweight of at least 2,000 grams per mole as measured by gel permeationchromatography. Those skilled in the art will understand that themolecular weight of the ligand can be determined prior to formation ofthe organic iridium complex, for example by analysis of the ligandprecursor by gel permeation chromatography. Alternatively, the molecularweight of may be determined indirectly by analysis of the polymericorganic iridium complex itself by gel permeation chromatography. In oneembodiment, the cyclometallated ligand is derived from a1-phenylisoquinoline, a 2-phenylpyridine, a 1-styryl isoquinoline, or acombination thereof.

Any of the ligands of the ligands present in the polymeric organiciridium complex may be deuterated. In one embodiment, all of the ligandsof the polymeric organic iridium complex are deuterated. In oneembodiment, at least one of the cyclometallated ligand and ketopyrroleligand is at least 10 percent deuterated. In another embodiment, atleast one of the cyclometallated ligand and ketopyrrole ligand is atleast 50 percent deuterated.

In one embodiment, polymeric organic iridium complex comprises apolymeric ligand derived from a polymeric cyclometallated ligandprecursor, for example a polymeric 1-phenylisoquinoline. In anotherembodiment, the polymeric organic iridium complex comprises a polymericligand derived from a polymeric ketopyrrole ligand precursor (e.g. apolymeric ketopyrrole). In one embodiment, the polymeric organic iridiumcomplex comprises at least two polymeric ligands. In one embodiment, thepresent invention provides a polymeric organic iridium complexcomprising a polymeric cyclometallated ligand derived from acyclometallated ligand precursor selected from the group consisting of apolymeric 1-phenylisoquinoline, a polymeric 1-styrylisoquinoline, apolymeric 2-phenylpyridine, and a combination thereof.

In another embodiment, the polymeric organic iridium complex is preparedfrom a non-polymeric organic iridium complex of the present invention.It is stressed that the terms “organic iridium complex” and“non-polymeric organic iridium complex” are interchangeable terms, havethe same meaning, and are distinct from the polymeric organic iridiumcomplexes of the present invention. In one embodiment, a non-polymericorganic iridium complex comprises one or more reactive functional groupswhich are used to incorporate the non-polymeric organic iridium complexinto a polymer chain in a polymerization step. For example, treatment ofthe non-polymeric organic iridium complex shown in Entry 8f of Table 8with bisphenol A and phosgene under interfacial polycarbonatepolymerization conditions (i.e. in a mixture comprising water, methylenechloride, a stoichiometric amount of sodium hydroxide, and a catalyticamount of hexaethylguanidinium chloride phase transfer catalyst) affordsa copolycarbonate comprising structural units derived from bisphenol Aand structural units derived from the non-polymeric organic iridiumcomplex, the two hydroxy groups of the ketopyrrole ligand present in thecomposition of Entry 8f (Table 8) serving as points of attachment to thepolymer chain. As those skilled in the art will appreciate, under suchcircumstances, it is possible for a single polymer chain to comprisemultiple iridium complexes arrayed along the polymer backbone. Ininstances where the non-polymeric organic iridium complex comprises buta single functional group susceptible to reaction under polymerizationconditions, the non-polymeric organic iridium complex may serve as anorganometallic endcapping agent, providing a polymeric speciesincorporating organic iridium complexes at the polymer chain ends. Inone embodiment, the non-polymeric organic iridium complex used toprepare the polymeric organic iridium complex is enantiomericallyenriched. Further examples of polymeric organic iridium complexesprovided by the present invention are provided in the Examples sectionof this disclosure.

As noted, in one embodiment, the polymeric organic iridium complexincorporates a polymeric ligand having a number average molecular weight(M_(n)) of at least 2,000 grams per mole as determined by gel permeationchromatography. In another embodiment, the polymeric organic iridiumcomplex incorporates a polymeric ligand having a M_(n) of at least 5,000grams per mole as determined by gel permeation chromatography. In yetanother embodiment, the polymeric organic iridium complex incorporates apolymeric ligand having a M_(n) of at least 10,000 grams per mole asdetermined by gel permeation chromatography.

From the preceding discussion it will be apparent that in one aspect,the polymeric organic iridium complexes of the present inventioncomprise one or more polymer chains incorporating a polymeric ligand. Awide variety of polymer types may comprise the polymer chains. Suitablepolymer types may include homopolymers, alternating copolymers, blockcopolymers, terpolymers, graft copolymers, star-burst polymers,condensation polymers, addition polymers, branched polymers, crosslinkedpolymers, thermoplastic polymers, thermosetting polymers, and the like.Exemplary polymer types which may comprise the polymer chain include,but are not limited to, conjugated polymers, olefin polymers,polycarbonates, ABS, EVA, HDPE, nylon, PET, PEN, and the like. In oneembodiment, the polymeric ligand is selected from the group consistingof polycarbonates, polyarylates, polyacrylates, and polyamides. Inanother embodiment, the polymeric ligand is an electroactive polymer. Inyet another embodiment, polymeric ligand comprises an electroluminescentpolymer. In certain embodiments, the polymeric organic iridium complexcomprises at least one ligand which is electroluminescent, for example aligand which is a polyfluorene. Those skilled in the art will understandthat the polymeric ligand must comprise appropriate functionality tobind to the iridium ion present in the polymeric organic iridiumcomplex. Thus, it will be understood that a ligand which is, forexample, a polyfluorene will be bound to the iridium ion either by acyclometallated ligand moiety or a ketopyrrolic ligand moiety.

In one embodiment, the polymeric organic iridium complex has structureXV

wherein each of the ligands

is independently at each occurrence a cyclometallated ligand which maybe the some or different;R² is independently at each occurrence a deuterium atom, a halogen, anitro group, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; and“a” is an integer from 0 to 3;and wherein the substructure

is a polymer chain.

Exemplary polymeric organic iridium complexes of the present inventionare given in Table 16. Each of Entries 16a-16e represents a chemicalspecies encompassed by generic formula XV and each of these compositionscomprises a polymer chain terminated at each chain end by an organiciridium complex. Each of the compositions Entries 16a-16e may be derivedfrom a non-polymeric organic iridium complex XVI via Suzuki coupling inwhich the non-polymeric organic iridium complex acts as a endcappingagent in the polymerization. The composition of Entry 16a, for example,comprises a poly(9,9-dioctyl fluorene)polymer chain having a numberaverage molecular weight of about 8,000 grams per mole, said polymerchain being terminated at each end by a benzoylpyrrole ligand bound toan iridium ion, the iridium ion being bound to two “ppy” ligands. Thus,the composition of Entry 16a contains two benzoylpyrrole ligands, twoiridium ions, and four “ppy” ligands. It should be noted that thecomposition of Entry 16a (and also those of Entries 16b-16e) is aspecies encompassed by generic structure XV wherein the polymer chain

of structure XV, itself comprises an organic iridium complex. Forconvenience of representation, this second organic iridium complex isnot shown, but it will be understood to be part of the polymer chain

of structure XV when this structure is used to represent the compositionof Entry 16a (or 16b-16e). The composition of Entry 16a can be preparedby copolymerizing, via Suzuki coupling, organic iridium complex XVI,wherein the cyclometallated ligands are each derived from2-phenylpyridine (i.e. “ppy” ligands), with a mixture of2,7-dibromo-9,9-dioctylfluorene and9,9-dioctylflouren-2,7-diyl-bistrimethyleneborate. The composition ofEntry 16b comprises four fully deuterated cyclometallated (D₈)ppyligands derived from perdeutero-2-phenylpyridine (C₁₁D₉N) and may beprepared analogously to Entry 16a via Suzuki coupling. The polymericorganic iridium complexes of Entries 16c and 16d are similarly preparedfrom the non-polymeric organic iridium complex XVI wherein thecyclometallated ligands are derived from 1-phenylisoquinoline andhexadeutero 1-phenylisoquinoline (“(D₆)piq”) respectively. The polymerchain structure shown for the composition of Entry 16c is designated“F8-TFB copolymer”. (D₆)piq refers to a partially deuterated “piq”ligand and is derived from 1-phenylisoquinoline comprising aperdeutero-isoquinoline ring (C₁₅D₆H₅N). (D₁₀)piq refers to a fullydeuterated “piq” ligand and is derived from perdeutero1-phenylisoquinoline (C₁₅D₁₁N). The composition of Entry 16e is preparedanalogously to the composition of Entry 16a.

TABLE 16 Exemplary Polymeric Organic Iridium Complexes XV ComprisingTerminal Organic Iridium Complexes Entry

R² “a” Polymer Chain

Mn^(†) 16a ppy — 0 poly(9,9-dioctyl fluorene) 8,000 16b (D₈)ppy — 0poly(9,9-dioctyl fluorene) 15,000  16c piq — 0

7,000 F8-TFB copolymer 16d (D₆)piq — 0 F8-TFB copolymer 10,000  16e(D₁₀)piq — 0 poly(9,9-dioctyl fluorene) 5,000 ^(†)number averagemolecular weight of the polymer chain 

Thus, in one embodiment, polymeric organic iridium complexes such as XVare derived from a non-polymeric organic iridium complex having a singlefunctional group that is reacted with a corresponding reactive group ona unit that is part of a polymer, an oligomer, or a monomer susceptibleto polymerization. In some embodiments, the organic iridium complexrepresents a pendant group, rather than a terminal group, on a polymerchain. For example, copolymerization of styrene with an organic iridiumcomplex having structure XVII will produce an olefin copolymercomprising pendant organic iridium complexes and phenyl rings assubstructures arrayed along a polyethylene chain. Exemplarynon-polymeric organic iridium complexes from which polymeric organiciridium complexes having structure XV may be derived include compoundshaving structures XVI-XVIII

and combinations thereof.

Further exemplary polymeric organic iridium complexes of the presentinvention encompassed by structure XV are given in Table 17. Each of thepolymeric organic iridium complex compositions illustrated in Table 17(Entries 17a-17c) represents a species encompassed by generic formula XVcomprising structural units derived from non-polymeric organic iridiumcomplex XVII arrayed along a polymer chain. Those skilled in the artwill appreciate that generic structure XV does not impose a conditionthat the structural unit comprising an iridium center be attached at theend of polymer chain. Structure XV merely indicates that the structuralunit comprising an iridium center forms some part of a polymer chain.Thus, generic structure XV encompasses polymeric organic iridiumcomplexes such as the compositions of Entries 17a-17c in which thestructural units comprising an iridium center are arrayed along thelength of a polymer chain. Also generic structure XV encompassespolymeric organic iridium complexes comprising structural unitscomprising an iridium center which are present only at the polymer chainends. From this discussion it will be understood by those skilled in theart that the polymeric organic iridium complex may comprise multiplestructural units comprising an iridium center.

TABLE 17 Polymeric Organic Iridium Complexes XV Comprising PendantOrganic Iridium Complexes Entry

R² “a” Polymer Chain

M_(n) ^(†) 17a ppy 0 — Copolymer prepared by poly- 35,000 merization ofa mixture comprising 4 mole percent vinyl monomer XVII and 96 molepercent styrene 17b ppy 0 — Copolymer prepared by poly-  9,000merization of a mixture comprising 3 mole percent vinyl monomer XVII and97 mole percent N- vinylcarbazole 17c piq 0 — Copolymer prepared bypoly- 27,000 merization of a mixture comprising 5 mole percent vinylmonomer XVII and 94 mole percent N-vinylcar- bazole and 2 mole percentdivinylbenzene M_(n) ^(†)is the number average molecular weight (GPC) ofthe polymer chain inclusive of the molecular weight contributions ofpendant organic iridium complex subunits.

Those skilled in the art will appreciate that the functional groupsshown in structure XVI (aryl bromide), structure XVII (vinyl), andstructure XVIII (amino) may be reacted with functional groups having acomplimentary reactivity to form polymeric species. Groups havingcomplementary reactivity to the aryl bromide group include, for example,boronic acid groups under Suzuki coupling conditions. Groups havingcomplementary reactivity to the vinyl group of structure XVII include,for example, vinyl monomers such as styrene, acrylonitrile, methylmethacrylate, methyl acrylate, polyacrylates such as Sartomer 454, andthe like under olefin polymerization conditions. Groups havingcomplementary reactivity to the amino group of structure XVIII includethe anhydride groups of an anhydride-terminated polymeric species, forexample an anhydride-terminated polyetherimide having a number averagemolecular weight of about 10,000 grams per mole as determined by gelpermeation chromatography, prepared by reaction of a molar excess ofbisphenol A dianhydride (BPADA) with meta-phenylene diamine. Thoseskilled in the art will appreciate that many additional conventionalfunctional groups are available for use in the preparation of polymericorganic iridium complexes from organic iridium complexes analogous tocompounds XVI-XVIII.

Conventional polymerization conditions may be used to provide many ofthe polymeric organic iridium complexes of the present invention. Forexample, in one embodiment, an organic iridium complex comprising aamine group (e.g. monomeric organic iridium complex XVIII wherein thetwo cyclometallated ligands are derived from 2-phenylpyridine) may beadded as a co-reactant to a reaction mixture comprising toluenediisocyanate and N,N′-dimethyl hexamethylenediamine in toluene to form apolyurea comprising chain terminal structural units derived from theiridium complex XVIII.

In certain embodiments, the polymeric organic iridium complex may beprepared from a multifunctional organic iridium complex selected fromthe group consisting of organic iridium complexes XIX, XX, XXI, and acombination thereof. Organic iridium complexes susceptible toincorporation into polymer structural units other than the end groups ofthe polymer (e.g. polymer repeat units) are at times herein referred toas monomeric organic iridium complexes. For example, organic iridiumcomplex XVII may be employed as a vinyl monomer in a copolymerizationreaction with styrene wherein the product copolymer comprises repeatunits derived from styrene and repeat units derived from the organiciridium complex XVII. Similarly, organic iridium complexes XIX, XX, XXIare at times herein referred to as monomeric organic iridium complexes.The generic cyclometallated ligands of monomeric organic iridiumcomplexes XIX, XX, XXI may be, for example, any of the cyclometallatedligands discussed herein. In one embodiment, the cyclometallated ligandsare derived from 1-phenylisoquinoline. In an alternate embodiment, thecyclometallated ligands are derived from 2-phenylpyridine.

While monomeric organic iridium complexes XIX-XXI feature a substitutedphenyl moiety bearing two reactive groups in the ketopyrrole ligand,those skilled in the art will appreciate that a variety of othersubstituted moieties bearing reactive groups are possible are possible,for example a multifunctional naphthyl moiety, a multifunctional tolylmoiety, a multifunctional 2-anthracenyl moiety, and the like. Thoseskilled in the art will understand that divinyl monomers such as organiciridium complex XXI may be useful as crosslinking agents in thepreparation of olefin polymers comprising organic iridium complexes.

In one embodiment, the present invention provides a polymeric organiciridium complex prepared by condensation polymerization of a monomericorganic iridium complex with suitable co-monomers under conventionalcondensation polymerization conditions. In one embodiment, a polyimidemay be synthesized by reacting a diamine containing iridium complex XXwith a suitable dianhydride.

As noted, in one embodiment, the present invention provides a polymericorganic iridium complex comprising a polymeric cyclometallated ligand.Polymeric organic iridium complexes of this type may be prepared, forexample, via Suzuki coupling of for example,2,7-dibromo-9,9-dioctylfluorene with9,9-dioctylflouren-2,7-diyl-bistrimethyleneborate in the presence of anorganic iridium complex having structure XXII. Those skilled in the artwill understand that under such circumstances the product polymer willcomprise structural units derived from organic iridium complex XXII.

In one embodiment, the present invention provides a light emittingpolymer composition comprising one or more of the polymeric organiciridium complexes disclosed herein.

In one embodiment, the light emitting polymer composition comprises atleast one polymeric component in addition to the polymeric organiciridium complex. The polymeric component in addition to the polymericorganic iridium complex is not particularly limited and may for examplebe any of the polymer compositions disclosed herein. In one embodiment,the polymeric component in addition to the polymeric organic iridiumcomplex is an electroactive polymer, for example an electroluminescentpolymer such as poly(9,9-dioctyl fluorene).

In one embodiment, the present invention provides a light emittingpolymer composition comprising a polymeric organic iridium complex,wherein the polymeric organic iridium complex comprises at least onecyclometallated ligand derived from a 1-phenylisoquinoline, a2-phenylpyridine, a 1-styrylisoquinoline, or a mixture thereof; and atleast one polymeric ketopyrrole ligand. In one embodiment, the presentinvention provides a polymeric organic iridium complex comprisingstructural units XXIII

wherein each of the substructures

is a polymer chain. In one embodiment, the polymer chains are bisphenolA polycarbonate chains terminated by groups derived frompara-cumylphenol. In an alternate embodiment of the present inventionthe polymer chains each comprise at least one organic iridium complexsubstructure derived from the monomeric organic iridium complex of Entry8f in Table 8.

As noted, in one embodiment, the present invention provides novelketopyrroles which are useful, for example. In the preparation of theorganic iridium complexes of the present invention. Thus, in oneembodiment, the present invention provides a composition comprisingketopyrrole XXIV

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical;“a” is on integer from 0 to 3; andX¹ and X² are independently at each occurrence a bromine atom, a hydroxygroup, or the group OR¹⁰;wherein the group R¹⁰ is independently at each occurrence a deuteriumatom, a halogen, a nitro group, an amino group, a C₃-C₄₀ aromaticradical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical.

Ketopyrroles encompassed by generic structure XXIV are illustrated by2-(3,5-dimethoxybenzoyl)-5-methylpyrrole,2-(3,5-dimethoxybenzoyl)pyrrole,2-(3,5-dihydroxybenzoyl)-5-methylpyrrole,2-(3,5-dihydroxybenzoyl)pyrrole,2-(3,5-dimethoxybenzoyl)-5-t-butylpyrrole,2-(3,5-dimethoxybenzoyl)-3,4,5-trideuteriopyrrole,2-(3,5-dibromobenzoyl)-5-methylpyrrole, 2-(3,5-dibromobenzoyl)-pyrrole2-(3,5-bis(trimethylsilyloxy)benzoyl)pyrrole,bis(t-butyldimethylsilyloxy)benzoyl)pyrrole, and the like.

In a particular embodiment, the group R¹⁰ is a C₁-C₅₀ aliphatic radical,for example a methacryloyl group. In another embodiment, the group R¹⁰is deuterated, i.e. R¹⁰ comprises deuterium in an amount which exceedsthe natural abundance level of deuterium ordinarily anticipated. In oneembodiment, the group R¹⁰ is at least 10 percent deuterated. In anotherembodiment, the group R¹⁰ is at least 50 percent deuterated. In yetanother embodiment, the present invention provides a ketopyrrole XXIV inwhich R² is deuterium, “a” is 3, and at least one of X¹ and X² are thegroup OR¹⁰ wherein R¹⁰ is at least 50 percent deuterated.

As the illustrative examples show, in certain embodiments the groups X¹and X² are identical, for example when both X¹ and X² are bromine atomsas in 2-(3,5-dibromobenzoyl)-5-bromopyrrole, hydroxy groups as in2-(3,5-dihydroxybenzoyl)pyrrole, methoxy groups as in2-(3,5-dimethoxybenzoyl)pyrrole, or methacryloyloxy groups as in2-(3,5-dimethacryloyloxybenzoyl)pyrrole.

In one embodiment, the present invention provides novel deuteratedketopyrroles having structure XXV

wherein R², “a”, X¹, and X² are defined as in structure XXIV.Ketopyrroles encompassed by generic structure XXV are illustrated by2-(3,5-dimethoxy-2,4,6-trideuteriobenzoyl)-5-methylpyrrole,2-(3,5-dimethoxy-2,4,6-trideuteriobenzoyl)-pyrrole,2-(3,5-dihydroxy-2,4,6-trideuteriobenzoyl)-5-methylpyrrole,2-(3,5-dihydroxy-2,4,6-trideuteriobenzoyl)pyrrole,2-(3,5-dimethoxy-2,4,6-trideuteriobenzoyl)-5-t-butylpyrrole,2-(3,5-dimethoxy-2,4,6-trideuteriobenzoyl)-3,4,5-trideuteriopyrrole,2-(3,5-dibromo-2,4,6-trideuteriobenzoyl)pyrrole,2-(3,5-dibromo-2,4,6-trideuteriobenzoyl)-3,4,5-trideuteriopyrrole,2-(3,5-bis(trimethylsilyloxy)-2,4,6-trideuteriobenzoyl)pyrrole,bis(trimethylsilyloxy)-2,4,6-trideuteriobenzoyl)-3,4,5-trideuteriopyrrole,bis(t-butyldimethylsilyloxy)-2,4,6-trideuteriobenzoyl)pyrrole, andbis(t-butyldimethylsilyloxy)-2,4,6-trideuteriobenzoyl)-3,4,5-trideuteriopyrrole.

In one embodiment, the present invention provides an organic iridiumcomplex comprising structural units derived from at least one ofbenzoylpyrroles XXIV or XXV. Thus, in one embodiment, the presentinvention provides an organic iridium complex comprising (i) at leastone cyclometallated ligand and (ii) at least one ketopyrrole ligand,wherein said ketopyrrole ligand is derived from ketopyrrole XXIV or XXV.

The organic iridium compositions of the present invention whetherpolymeric or non-polymeric typically display strong charge transferbands in their UV-Vis absorption spectra. Such absorption bands arebelieved to result from the transfer of electrons from molecularorbitals that are primarily ligand in character to molecular orbitalsthat are primarily metal in character, or alternatively, transfer ofelectrons from molecular orbitals that are primarily metal in characterto molecular orbitals that are primarily ligand in character. Suchcharge transfer events are designated variously as Ligand-to-MetalCharge Transfer (LMCT) or Metal-to-Ligand Charge Transfer (MLCT). Incertain embodiments the organic iridium compositions provided by thepresent invention are characterized by highly emissive excited statesthat may be produced when a voltage is applied. Materials possessingsuch properties are useful in the preparation of electronic devices, forexample organic light emitting diodes (OLEDs). Other applications inwhich the organic iridium complexes of the present invention may be usedinclude light emitting electrochemical cells, photo detectors,photoconductive cells, photo switches, phototransistors, and phototubes.Thus, in one embodiment, the present invention provides an electronicdevice comprising at least one electroactive layer comprising an organiciridium composition of the present invention.

The organic iridium compositions of the present invention areparticularly well suited for use in an electroactive layers in organiclight emitting devices. In one embodiment, the present inventionprovides an organic light emitting device comprising an electroactivelayer which consists essentially of the organic iridium composition. Inanother embodiment, the present invention provides an organic lightemitting device comprising the organic iridium composition as aconstituent of an electroactive layer of an organic light emittingdevice. In one embodiment, the present invention provides an organiclight emitting device comprising the organic iridium composition as aconstituent of a light emitting electroactive layer of an organic lightemitting device.

In one embodiment, the present invention provides an electronic devicecomprising a one or more of the polymer compositions of the invention.It has been found that in certain embodiments device performance maydepend upon the physical properties of these polymer compositions, forexample good film-forming abilities, good film strength, high glasstransition temperature, good temperature resistance, and the like. Incertain embodiments, the polymeric compositions provided by the presentinvention show enhanced solubility allowing the preparation of solventcast films properties using techniques such as spin casting.

In one embodiment, the invention provides an organic light emittingdevice comprising at least one of the organic iridium compositionsprovided by the present invention. An organic light emitting devicetypically comprises multiple layers which include in the simplest case,an anode layer and a corresponding cathode layer with an organicelectroluminescent layer disposed between said anode and said cathode.When a voltage bias is applied across the electrodes, electrons areinjected by the cathode into the electroluminescent layer whileelectrons are removed from (or “holes” are “injected” into) theelectroluminescent layer from the anode. Light emission occurs as holescombine with electrons within the electroluminescent layer to formsinglet or triplet excitons, light emission occurring as singletexcitons transfer energy to the environment by radiative decay. Tripletexcitons, unlike singlet excitons, typically cannot undergo radiativedecay and hence do not emit light except at very low temperatures.Theoretical considerations dictate that triplet excitons are formedabout three times as often as singlet excitons. Thus the formation oftriplet excitons, represents a fundamental limitation on efficiency inorganic light emitting devices which are typically operated at or nearambient temperature. In one aspect, the organic iridium compositionsprovided by the present invention may serve as precursors to lightemissive, short-lived excited state species which form as the normallyunproductive triplet excitons encounter and transfer energy to theorganic iridium composition. Thus, in one aspect, the present inventionprovides more efficient organic light emitting devices comprising atleast one of the organic iridium compositions of the present invention.

In this disclosure, the organic electroluminescent layer is at timesreferred to as a “bipolar emission layer” and, as the previousdiscussion suggests, is a layer within an organic light emitting devicewhich when in operation contains a significant concentration of bothelectrons and holes and provides sites for exciton formation and lightemission. Other components which may be present in an organic lightemitting device include: a “hole injection layer” which is defined as alayer in contact with the anode which promotes the injection of holesfrom the anode into the interior layers of the OLED; and an “electroninjection layer” which is defined as a layer in contact with the cathodethat promotes the injection of electrons from the cathode into the OLED;an “electron transport layer” which is defined as a layer whichfacilitates conduction of electrons from cathode to a chargerecombination site. The electron transport layer need not be in contactwith the cathode, and frequently the electron transport layer is not anefficient hole transporter and thus it serves to block holes migratingtoward the cathode. During operation of an organic light emitting devicecomprising an electron transport layer, the majority of charge carriers(i.e. holes and electrons) present in the electron transport layer areelectrons and light emission can occur through recombination of holesand electrons present in the electron transport layer. Additionalcomponents which may be present in an organic light emitting deviceinclude: a “hole transport layer” which is defined as a layer which whenthe OLED is in operation facilitates conduction of holes from the anodeto charge recombination sites and which need not be in contact with theanode; and an “exciton-hole transporting layer” which is defined aslayer which when the OLED is in operation facilitates the conduction ofholes from the anode to charge recombination sites, and in which themajority of charge carriers are holes, and further in which excitons,typically triplet excitons, are also present and mobile, but do not emitlight. Yet an additional component which may be present in an organiclight emitting device is an “exciton-electron transporting layer” whichis defined as a layer which when the OLED is in operation facilitatesthe conduction of electrons from the cathode to charge recombinationsites, and in which the majority of charge carriers are electrons, andin which excitons, typically triplet excitons, are present and mobile,but do not emit light. Still yet additional components which may bepresent in an organic light emitting device include: a “holetransporting emission layer” which is defined as a layer in which whenthe OLED is in operation facilitates the conduction of holes to chargerecombination sites, and in which the majority of charge carriers areholes, and in which emission occurs not only through recombination withresidual electrons, but also through the transfer of energy from acharge recombination zone elsewhere in the device; and an “electrontransporting emission layer” which is defined as a layer in which whenthe OLED is in operation facilitates the conduction of electrons tocharge recombination sites, and in which the majority of charge carriersare electrons, and in which emission occurs not only throughrecombination with residual holes, but also through the transfer ofenergy from a charge recombination zone elsewhere in the device.

FIGS. 1-11 illustrate various embodiments of organic light emittingdevices provided by the present invention. FIG. 1 illustrates a simpleorganic light emitting device comprising an anode 10 and a cathode 20with composition 30, a bipolar emissive material comprising an organiciridium composition of the present invention, disposed as a layerbetween the anode 10 and the cathode 20. Materials suitable for use asthe anode 10 are illustrated by materials having a bulk conductivity ofat least about 100Ω/(ohms per square), as measured by a four-point probetechnique. Indium tin oxide (ITO) is typically used as the anode becauseit is substantially transparent to light transmission and thusfacilitates the escape of light emitted from electro-active organiclayer. Other materials which may be utilized as the anode layer includetin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tinoxide, antimony oxide, and mixtures thereof.

Materials suitable for use as the cathode 20 are illustrated by zerovalent metals which can inject negative charge carriers (electrons) intothe inner layer(s) of the OLED. Various zero valent metals suitable foruse as the cathode 20 include K, Li, Na, Cs, Mg, Ca, Sr, Ba, Al, Ag, Au,In, Sn, Zn, Zr, Sc, Y, elements of the lanthanide series, alloysthereof, and mixtures thereof. Suitable alloy materials for use as thecathode layer include Ag—Mg, Al—Li, In—Mg, Al—Ca, and Al—Au alloys.Layered non-alloy structures may also be employed as the cathode, forexample a thin layer of a metal such as calcium, or a metal fluoride,such as LiF, covered by a thicker layer of a zero valent metal, such asaluminum or silver. In one embodiment, the cathode consists essentiallyof a single zero valent metal, for example a cathode consistingessentially of aluminum metal. The cathode may be deposited on theunderlying element by physical vapor deposition, chemical vapordeposition, sputtering, or like technique. In one embodiment the cathodeis transparent. The term “transparent” means allowing at least 50percent, commonly at least 80 percent, and more commonly at least 90percent, of light in the visible wavelength range to be transmittedthrough at an incident angle of less than or equal to 10 degrees. Thismeans that a device or article, for example a cathode, described asbeing “transparent” will transmit at least 50 percent of light in thevisible range which impinges on the device or article at an incidentangle of about 10 degrees or less.

Composition 30, a bipolar emissive material comprising an organiciridium composition of the present invention, is illustrated by any ofthe non-polymeric and polymeric iridium compositions of the presentinvention. For example, composition 30 may consist entirely of anon-polymeric organic iridium complex (e.g. organic iridium complex X).Or, composition 30 may be a polymer composition comprising both anon-polymeric organic iridium complex (e.g. organic iridium complex X)and a polymeric component (e.g. poly(9,9-dioctyl fluorene) having anumber average molecular weight of about 8,000 grams per mole). Orcomposition 30 may consist essentially of a polymeric organic iridiumcomplex (e.g. the polymeric organic iridium complex of Example 34). Orcomposition 30 may comprise a polymeric organic iridium complex and anadditional component (e.g. a mixture of the polymeric organic iridiumcomplex of Example 34 and PDOT:PSS). In one embodiment, composition 30may comprise any of the bipolar emissive materials 33 described hereintogether with at least one organic iridium complex or polymeric organiciridium complex of the invention.

FIG. 2 illustrates a organic light emitting device provided by thepresent invention further comprising a hole injection layer 40 disposedbetween the anode 10 and the bipolar emissive layer 30, of the organiclight emitting device of FIG. 1. Materials suitable for use as holeinjection layers are illustrated by BAYTRON commercially available fromH.C. Stark, Inc. and hole injection layer (HIL) materials available fromAir Products Corporation. Hole injection layer materials obtained fromAir Products, Inc. are also referred to at times herein (or insupporting laboratory notebook records) as “AP-71”, “AP-82” and “AirProducts HIL conducting polymer”.

FIG. 3 illustrates an organic light emitting device provided by thepresent invention further comprising an electron transport layer 50disposed between the cathode 20 and the bipolar emissive layer 30, ofthe organic light emitting device of FIG. 2. Materials suitable for useas the electron transport layer are illustrated by poly(9,9-dioctylfluorene); tris(8-hydroxyquinolato) aluminum (Alq₃);2,9-dimethyl-4,7-diphenyl-1,1-phenanthroline;4,7-diphenyl-1,10-phenanthroline;2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole;3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole, and thelike.

FIG. 4 illustrates an organic light emitting device provided by thepresent invention comprising an anode 10 and a cathode 20, a bipolaremissive layer 33, a hole injection layer 40, and a hole transport layer36 comprising at least one of the organic iridium compositions providedby the present invention. Materials suitable for use in the bipolaremission layer 33 are illustrated by electroluminescent polymers such aspoly(9,9-dioctyl flourene), F8-TFB copolymer, and the like. Materialssuitable for use in layer 36 include compositions comprising a holetransport material such as 1,1-bis((di-4-tolylamino)phenyl)cyclohexane,N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-(1,1′-(3,3′-dimethyl)biphenyl)-4,4′-diamine,tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine,phenyl-4-N,N-diphenylaminostyrene, p-(diethylamino)benzaldehydediphenylhydrazone, triphenylamine,1-phenyl-3-(p-(diethylamino)styryl)-5-(p-(diethylamino)phenyl)pyrazoline,1,2-trans-bis(9H-carbazol-9-yl)cyclobutane,N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine, copperphthalocyanine, polyvinylcarbazole, (phenylmethyl)polysilane;poly(3,4-ethylendioxythiophene) (PEDOT), polyaniline, and the like; andat least one organic iridium composition provided by the presentinvention.

FIG. 5 illustrates an organic light emitting device provided by thepresent invention comprising an anode 10, a cathode 20, a bipolaremissive layer 33, a hole injection layer 40, an electron transportlayer 50, and an electron transport layer 55 comprising at least one ofthe organic iridium compositions provided by the present invention.Materials suitable for use in layer 55 include compositions comprisingat least one electron transport material (e.g. Alq₃) and at least oneorganic iridium composition of the present invention (e.g. organiciridium complex VIII).

FIG. 6 illustrates the organic light emitting device of FIG. 4 furthercomprising a second hole transport layer 60 disposed between the holeinjection layer 40 and the first hole transport layer 36, said holetransport layer 36 comprising at least one organic iridium compositionof the present invention and a hole transport material. Materialssuitable for use in hole transport layer are illustrated by the listingof hole transport materials presented in the discussion of FIG. 4.

FIG. 7 illustrates the organic light emitting device of FIG. 6 furthercomprising a exciton-hole transporting layer 70. Materials suitable foruse in exciton-hole transporting layer are illustrated by F8-TFBcopolymer.

FIG. 8 illustrates the organic light emitting device of FIG. 7 whereinthe bipolar emission layer 33 is replaced by 30, a bipolar emissivematerial comprising an organic iridium composition of the presentinvention.

FIG. 9 illustrates an organic light emitting device provided by thepresent invention comprising an anode 10, a cathode 20, a bipolaremissive composition 30 comprising an organic iridium composition of thepresent invention disposed between the cathode and a hole transportlayer 60, and a hole injection layer 40.

FIG. 10 illustrates the organic light emitting device of FIG. 9 whereinan electron transport layer 50 is disposed between the cathode 20 andthe bipolar emissive composition 30 comprising an organic iridiumcomposition of the present invention.

FIG. 11 illustrates an organic light emitting device provided by thepresent invention comprising an anode 10, a cathode 20, a bipolaremissive layer 33, hole injection layer 40, a hole transport layer 60,and an exciton-electron transporting layer 75. Materials suitable foruse in the exciton-electron transporting layer 75 include polyfluoreneand derivatives of polyfluorene, e.g. poly(9,9-dioctyl fluorene).

EXAMPLES

Without further elaboration, it is believed that one skilled in the artcan, using the description herein, utilize the present invention to itsfullest extent. The following examples are included to provideadditional guidance to those skilled in the art in practicing theclaimed invention. The examples provided are merely representative ofthe work that contributes to the teaching of the present application.While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. Accordingly, these examples are not intended tolimit the invention, as defined in the appended claims, in any manner.

Thin layer chromatography (TLC) was performed on glass plates coatedwith silica-gel 60F (Merck 5715-7). The plates were inspected using UVlight. Column chromatography was carried out using silica-gel 60 (Merck9358, 230-400 mesh). All ¹H- and ¹³C NMR spectra were recorded on aBruker Advance 500 NMR spectrometer (at 500 MHz and 125 MHz,respectively) or a Bruker 400 NMR spectrometer (at 400 and 100 MHz,respectively). Chemical shifts were determined relative totetramethylsilane using the residual solvent peak as a referencestandard. High Resolution Mass spectra were measured with MALDI or Elion sources. MALDI Mass spectra were obtained using dithranol as thesupporting matrix.

Preparation of Chloride-Bridged Iridium Dimer Intermediates GeneralProcedure

To a nitrogen purged solution containing a mixture of 2-methoxyethanoland water was added IrCl₃.xH₂O (Strem Chemicals) followed by theaddition of the cyclometallating ligand precursor (2.5-3.8 equiv.). Theresulting mixture was heated at reflux for 15-48 h and the product wascollected by vacuum filtration. In the following examples, theabbreviations “ppy”, “piq”, “F₂ppy” and “C6” have the followingstructures shown in Table 18. The asterisks (*) signal the point ofattachment of the cyclometallated ligand to iridium.

TABLE 18 Chemical Ligand Name of Abbre- Ligand viation Ligand ChemicalStructure Precursor “ppy”

2-phenyl- pyridine “piq”

1-phenyl- isoquinoline “F₂ppy”

2-(2,4-di- fluoro- phenyl)- pyridine “C6”

Coumarin 6

Example 1

{(ppy)₂Ir(μ-Cl)}2: A mixture of 2-methoxyethanol and water (30 ml:10 mL)was degassed with N₂ for 15 min. To this solvent mixture was addedIrCl₃*xH₂O (0.388 g, 1.30 mmol) followed by 2-phenylpyridine (0.766 g,4.94 mmol) and the mixture was heated at reflux for 24 h under anatmosphere of N₂. The reaction mixture was cooled to room temperatureand the yellow precipitate was collected by filtration and washed withEtOH (50 mL), acetone (50 mL), and dried in air. The yellow precipitatewas dissolved in CH₂Cl₂ and filtered to remove an insoluble material.The solution was concentrated to dryness and filtered after beingsuspended in hexanes. Yield: 0.539 g, 77%. ¹H-NMR (400 MHz, CD₂Cl₂, 25°C.) δ 5.88 (d, 2H), 6.60 (m, 2H), 6.82 (m, 4H), 7.56 (d, 2H), 7.80 (m,2H), 7.94 (d, 2H), 9.25 (d, 2H).

Example 2

{(F₂ppy)₂Ir(μ-Cl)}₂: A mixture of 2-methoxyethanol and water (20 ml 10mL) was degassed with N₂ for 15 min. To this solvent mixture was addedIrCl₃.xH₂O (0.388 g, 1.30 mmol) followed by2-(2,4-difluorophenyl)-pyridine (0.766 g, 4.94 mmol) and the mixture washeated at reflux for 15 h under an atmosphere of N₂. The reactionmixture was cooled to room temperature and poured into MeOH (200 mL).The yellow precipitate was collected by filtration and washed with MeOHand hexanes until the filtrate washes were colorless. The yellowprecipitate was recrystallized from a mixture of toluene and hexanes toafford yellow needles. Yield: 2.20 g, 44%. ¹H-NMR (400 MHz, CD₂Cl₂, 25°C.) δ5.29 (m, 4H), 6.38 (m, 4H), 6.87 (m, 4H), 7.87 (m, 4H), 8.33 (m,4H), 9.12 (m, 4H).

Example 3

{(piq)₂Ir(μ-Cl)}₂: A mixture of 2-methoxyethanol and water (80 ml 20 mL)was degassed with N₂ for 15 min. To this solvent mixture was addedIrCl₃.xH₂O (4.00 g, 13.4 mmol) followed by 2-phenylisoquinoline (6.90 g,33.5 mmol) and the mixture was heated at reflux for 15 h under anatmosphere of N₂. The reaction mixture was cooled to room temperatureand poured into MeOH (200 mL). The red precipitate was collected byfiltration and washed with MeOH until the filtrate washes were colorlessand dried in air. Yield: 6.68 g, 77%. ¹H-NMR (500 MHz, CD₃SOCD₃, 25° C.)δ5.57 (d, 2H), 6.32 (d, 2H), 6.63 (t, 2H), 6.78 (t, 2H), 6.91 (t, 2H),7.02 (t, 2H), 7.89 (m, 10H), 8.03 (d, 2H), 8.18 (m, 8H), 8.90 (m, 4H),9.58 (d, 2H), 9.76 (d, 2H).

Example 4

{(C6)₂Ir(μ-Cl)}₂: A mixture of 2-methoxyethanol and water (12 ml: 1 mL)was degassed with N₂ for 10 min. To this solvent mixture was addedIrCl₃-xH₂O (0.254 g, 0.853 mmol) followed by Coumarin 6 (0.750 g, 2.13mmol) and the mixture was heated at reflux for 48 h under an atmosphereof N₂. The reaction mixture was cooled to room temperature, poured into500 ml of acetone and concentrated to dryness under reduced pressure.The residue was suspended in acetone (200 mL) and the insoluble orangeproduct was collected by filtration and washed with acetone until thefiltrate washes were colorless. Yield: 0.548 g, 69%. ¹H NMR (400 MHz,CD₂Cl₂, 25° C.) δ0.90 (t, 24H), 3.09 (m, 16H), 4.97 (d, 4H), 5.34 (m,4H), 6.12 (d, 4H), 7.06 (m, 8H), 7.37 (m, 4H), 7.84 (m, 4H).

Preparation of Ketopyrrole Ligands

General Procedure for the Preparation of N,N-Diethyl BenzamidePrecursors to Ketopyrrole Ligands, Method A:

To a stirred CH₂Cl₂ solution (20 mL) of the benzoyl chloride at −10° C.was added triethylamine (4 mL), followed by the dropwise addition ofdiethylamine (1.4 equivalents). The heterogeneous reaction mixture wasallowed to warm to room temperature and stirring was continued for 30minutes. The reaction mixture was then transferred to a separatoryfunnel containing H₂O (20 mL). The organic layer was separated andwashed with 5% HCl (2×25 mL), H₂O (25 ml), and dried over Na₂SO₄.Removal of the CH₂Cl₂ solvent afforded the product.

General Procedure for the Preparation of N,N-Diethyl BenzamidePrecursors to Ketopyrrole Ligands, Method B:

A mixture of thionyl chloride (6 mL) and the benzoic acid was heated atreflux until the starting benzoic acid dissolved. Excess thionylchloride was removed under reduced pressure leaving the crude acidchloride as a low melting solid which was used without furtherpurification. The crude acid chloride was dissolved in CH₂Cl₂(20 mL) andcooled to −10° C. To this stirred solution was added triethylamine (4mL), followed by the dropwise addition of diethylamine (1.4equivalents). The heterogeneous reaction mixture was allowed to warm toroom temperature and was stirred for 30 minutes. The reaction mixturewas transferred to a separatory funnel containing H₂O (20 mL). Theorganic layer was separated and washed with 5% HCl (2×25 mL), H₂O (25ml), and dried over Na₂SO₄. The solvent was removed under reducedpressure to afford the product N,N-diethyl benzamide.

Exemplary N,N-diethylbenzamides, precursors to ketopyrrole ligands,prepared during the course of this investigation are gathered in Table19 along with the method of preparation employed and the yield of theN,N-diethylbenzamide product.

TABLE 19 Product Benzamide Method Yield ¹³C NMR (100 MHz, CD₂Cl₂, 25°C.) δ N,N-diethyl-4- A 98% 13.1, 14.5, 39.9, 43.8, 123.5, 128.6, 132.1,137.1, bromobenzamide 170.4. N,N-diethyl-4- A 96% 13.2, 14.3, 14.4,21.2, 29.5, 31.9, 32.3, 36.3, 39.8, hexylbenzamide 43.7, 126.8, 128.8,135.5, 144.7, 171.6. N,N-diethyl-4- A 96% 13.2, 14.5, 39.8, 43.9, 157.8(d)*, 129.0 (d)*, fluorobenzamide 134.3, 162.3, 164.7, 170.5.N,N-diethyl-4- B 96% 13.2, 14.5, 21.6, 39.7, 43.8, 126.8, 129.4, 135.3,methylbenzamide 139.6, 171.6. N,N-diethyl-4- B 99% 13.5, 39.9, 43.7,55.8, 114.0, 128.6, 130.4, 160.8, methoxybenzamide 171.3N,N-diethyl-3,5- B 95% 13.1, 14.5, 40.0, 43.9, 123.5, 128.7, 135.1,141.4, dibromobenzamide 168.1. N,N-diethyl-3,5- B 98% 13.2, 14.6, 39.6,43.7, 56.0, 101.4, 104.5, 140.1, dimethoxybenzamide 161.4. 171.0.*doubletGeneral Procedure for Preparation of Ketopyrroles

Method C: A series of 2-aryl-ketopyrrole ligand precursors was preparedemploying the Vilsmeier-Hack aroylation of pyrrole with aN,N-diethylbenzamide. The benzamide derivative was treated with POCl₃ toafford the Vilsmeier salt which upon treatment with pyrrole affordedafter workup the ketopyrrole product in good yield. Thus, the benzamide(20 mmol) was dissolved in POCl₃(4 mL) and stirred at room temperaturefor 15 h. A solution of pyrrole (1.50 mL, 20 mmol) in 1,2-dichloroethane(50 mL) was then added and the mixture was stirred for 15 h. Thereaction mixture was then poured into stirred aqueous Na₂CO₃ (15.0 g in150 mL of H₂O). To the resultant two-phase mixture was added ethylacetate (EtOAc) and the mixture was heated at reflux for 4 h. Aftercooling to room temperature, the mixture was filtered and transferred toa separatory funnel and the layers were separated. The organic layer waswashed with H₂O (2×50 mL), dried over Na₂SO₄, and decolorized withcharcoal. The crude ketopyrrole was isolated as a solid upon removal ofthe solvents and was purified by recrystallization from CH₂Cl₂/hexanes.

Method D: Alternatively, ketopyrroles were prepared in a single step byreaction of a benzoic acid with N-tosylpyrrole in a mixture oftrifluoroacetic anhydride (TFAA) and CH₂Cl₂ at reflux. Thus, to astirred CH₂Cl₂(20 mL) solution containing N-tosyl pyrrole (CAS No.17639-64-4), maintained at −10° C., was added TFAA (trifluoroaceticanhydride, 50 mL), followed by the addition of the benzoic acidderivative in portions. The mixture was heated at reflux until TLCanalysis showed complete conversion (ca. 48 hrs) after which thesolvents were removed under reduced pressure. The residue was dissolvedin CH₂Cl₂(20 mL) and transferred to a separatory funnel. The organiclayer was washed with 10% NaHCO₃(4×100 mL), H₂O (2×100), dried overNa₂SO₄, filtered, and finally concentrated to dryness. The residue waspurified by column chromatography (SiO₂, EtOAc:Hexanes).

Exemplary ketopyrroles, prepared during the course of this investigationare gathered in Table 20 along with the method of preparation employedand the yield of the ketopyrrole product.

TABLE 20 Benzamide/Benzoic Acid Precursor Ketopyrrole Product MethodYield N,N-diethyl-4-bromobenzamide 2-(4-bromobenzoyl)pyrrole C 62%N,N-diethyl-4-hexylbenzamide 2-(4-hexylbenzoyl)pyrrole C 70%N,N-diethyl-4-fluorobenzamide 2-(4-fluorobenzoyl)pyrrole C 65%N,N-diethyl-4-methylbenzamide 2-(4-methylbenzoyl)pyrrole C 40%N,N-diethyl-4-methoxybenzamide 2-(4-methoxybenzoyl)pyrrole C 60%N,N-diethyl-3,5- 2-(3,5-dibromobenzoyl)pyrrole C 49% dibromobenzamideN,N-diethyl-3,5- 2-(3,5-dimethoxybenzoyl)pyrrole C 41%dimethoxybenzamide 4-(trifluoroacetylamino)-benzoic1-toluenesulfonyl-2-(4- D 99% acid (trifluoroacetylamino)-benzoyl)pyrrole 3,5-di(trifluoroacetylamino)- 1-toluenesulfonyl-2-(3,5-D 50% benzoic acid di(trifluoroacetylamino)- benzoyl)pyrrole4-(trifluoroacetylaminomethyl)- 1-toluenesulfonyl-2-(4- D 81% benzoicacid (trifluoroacetylaminomethyl)- benzoyl)pyrrole

The product ketopyrroles could be further elaborated to other usefulintermediates. In one instance, the dimethyl ether ketopyrrolederivative was converted into the corresponding bisphenol by treatmentwith BBr₃ in CH₂Cl₂. In addition to the preparation of simpleketopyrroles, more complex ketopyrroles such as2-benzoyl-3,4-benzopyrrole derivatives were prepared in one step byreacting ortho-aminoacetophenone with alpha-bromo-4-bromoacetophenone inhot DMF (dimethyl formamide). 2-Benzoyl-4,5-benzopyrrole is also attimes referred to herein as 2-benzoylindole.

Example 5

2-(3,5-Dihydroxybenzoyl)pyrrole: A solution of boron tribromide inCH₂Cl₂ was prepared by adding BBr₃(2.2 mL, 1 M in CH₂Cl₂) with stirringto CH₂Cl₂ (5 mL) at −78° C. under an inert atmosphere. To this solutionwas added (dropwise) a solution of 2-(3,5-dimethoxybenzoyl)pyrrole (200mg, 0.864 mmol) in CH₂Cl₂(1 mL). The cooling bath was removed and thereaction mixture stirred overnight at room temperature. The reactionmixture was then poured into a separatory funnel containing H₂O (20 mL)and EtOAc (20 mL). The layers were separated and the H₂O layer wasextracted with EtOAc (2×15 mL). The combined organic extracts were driedover Na₂SO₄, filtered and concentrated to afford the crude product assticky solid. Yield (135 mg, 77%). ¹H NMR (400 MHz, CD₃OD, 25° C.) δ6.28(m, 1H), 6.45 (t, 1H), 6.73 (d, 2H), 6.88 (m, 1H), 7.15 (m, 1H); ¹³C NMR(100 MHz, CD₃OD, 25° C.) δ107.0, 108.5, 111.6, 121.5, 127.5, 132.3,142.1, 159.8, 187.0; HRMS (EI): m/z 203.0560 (100) {M}⁺.

Example 6

2-(4-Bromobenzoyl)-3-methylindole: A mixture of ortho-aminoacetophenone(2.70 g, 20 mmol) and alpha-bromo-4-bromoacetophenone (5.56 g, 20 mmol)was dissolved in anhydrous DMF (50 mL) and heated at 90° C. for 14 hrs.The mixture was poured over crushed ice (1000 mL) and the precipitatewas collected by filtration. The crude product was subjected to flashchromatography through a column of silica gel using CH₂Cl₂:hexanes asthe eluant. The product 2-(4-bromobenzoyl)-3-methylindole, also referredto as 2-benzoyl-4,5-benzopyrrole, was recrystallized from CH₂Cl₂/hexanesas yellow needles. Yield (2.70 g, 45%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.)δ2.27 (s, 3H), 7.16 (m, 1H), 7.35 (m, 1H), 7.42 (m, 1H), 7.67 (m, 5H),8.98 (bs, 1H); ¹³C NMR (100 MHz, CD₂Cl₂, 25° C.) δ11.6, 112.4, 120.8,120.9, 121.8, 127.1, 127.2, 129.5, 131.0, 132.3, 137.2, 138.8, 188.4;HRMS (EI): m/z 313.0077 (100) {M}⁺.

Example 7

2-(4-Aminobenzoyl)pyrrole: To a stirred EtOH (4 mL) solution containingN-toluenesulfonyl-2-(4-(trifluoroacetylamino)benzoyl)pyrrole (0.500 g,1.15 mmol), was added 40% KOH solution (2 mL) and the mixture was heatedat reflux until thin layer chromatography (TLC) analysis showed completeconversion of the starting material. The resulting solution was cooledto room temperature and diluted with EtOAc (20 mL), and the mixture wasevaporated to dryness. The crude product was purified by columnchromatography (SiO₂, EtOAc:Hexanes) to afford the purified product2-(4-aminobenzoyl)pyrrole (196 mg, 94% yield). ¹H NMR (400 MHz, CD₂Cl₂,25° C.) δ4.19 (bs, 2H), 6.33 (m, 1H), 6.72 (d, 2H), 6.88 (m, 1H), 7.10(m, 1H), 7.82 (d, 2H), 9.90 (bs, 1H); ¹³C NMR (100 MHz, CD₂Cl₂, 25° C.)δ110.9, 114.2, 118.0, 124.5, 128.5, 131.8, 131.9, 151.3, 183.5; HRMS(EI): m/z 186.0793 (100) {M}⁺.

Example 8

2-(3,5-Diaminobenzoyl)pyrrole: To a stirred EtOH (10 mL) solution ofN-toluenesulfonyl-2-(3,5-di(trifluoroacetylamino)benzoyl)pyrrole (1.00g, 1.83 mmol), was added 40% KOH solution (2 mL) and the mixture washeated at reflux until TLC analysis showed complete conversion. Theresulting solution was cooled to room temperature and worked up as inExample 7. The crude product was purified by column chromatography(SiO₂, CH₂Cl₂:MeOH) to afford the purified product2-(3,5-diaminobenzoyl)pyrrole (237 mg, 65% yield). ¹H NMR (500 MHz,CD₃OD, 25° C.) δ 2.43 (s, 3H), 6.45 (m, 1H), 6.90 (m, 1H), 7.41 (d, 2H),7.88 (m, 3H), 7.93 (d, 2H), 8.39 (t, 1H); ¹³C NMR (100 MHz, CD₃OD, 25°C.) δ 104.8, 105.7, 109.4, 119.5, 125.2, 130.5, 139.8, 147.8, 186.0;HRMS (EI): m/z 201.0896 (100) {M}⁺.

Example 9

2-(4-Aminomethylbenzoyl)pyrrole: To a stirred EtOH (10 mL) solutioncontainingN-toluenesulfonyl-2-(4-(trifluoroacetylaminomethyl)benzoyl)pyrrole (1.00g, 2.20 mmol), was added 40% KOH solution (2 mL) and the mixture washeated at reflux until TLC analysis showed complete consumption of thestarting material. The reaction mixture was then cooled to roomtemperature worked up as in Example 7. The crude product was suspendedin H₂O, filtered and dried to afford the purified product2-(4-aminomethylbenzoyl)pyrrole (381 mg, 86%). ¹H NMR (500 MHz, CD₃OD,25° C.) δ2.43 (s, 3H), 4.53 (s, 2H), 6.42 (m, 1H), 6.77 (m, 1H), 7.41(d, 2H), 7.72 (d, 2H), 7.85 (m, 1H), 7.95 (d, 2H), 8.39 (t, 1H); ¹³C NMR(100 MHz, CD₃OD, 25° C.) δ44.6, 109.7, 119.4, 125.6, 126.5, 128.4,130.4, 136.8, 146.1, 184.6; HRMS (EI): m/z 200.0940 (100) {M}⁺.

Example 10

2-(3,5-Di(allyloxy)benzoyl)pyrrole: To a solution of2-(3,5-dihydroxybenzoyl)pyrrole (100 mg, 0.492 mmol) in DMF (2.0 mL) atroom temperature was added successively potassium carbonate (272 mg,1.97 mmol) and allyl bromide (236 mg, 1.97 mmol). The mixture wasstirred for 24 h, poured into water, and then extracted with Et₂O. Theextract was washed with brine, dried over Mg₂SO₄, and concentrated todryness. The resulting residue was subjected to column chromatography onsilica gel using CH₂Cl₂ as the eluant to give the purified product as acolorless oil. Yield (123 mg, 88%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ4.58 (m, 4H), 5.30 (m, 2H), 5.43 (m, 2H), 6.08 (m, 2H), 6.34 (m, 1H),6.70 (t, 1H), 6.92 (m, 1H), 7.03 (d, 2H), 7.17 (m, 1H), 9.8.3 (bs, 1H);¹³C NMR (100 MHz, CD₂Cl₂, 25° C.) δ69.7, 106.1, 108.2, 111.5, 118.0,119.7, 125.9, 131.6, 133.7, 140.8, 160.2, 184.4; HRMS (EI): m/z 283.1179(100) {M}⁺.

Preparation of Organic Iridium Complexes

General Methods: The organic iridium complexes (Ir(III) complexes)provided by the invention were prepared by contacting the N-tosyl- orunprotected ketopyrrole ligand precursor in 2-methoxyethanol with excesssodium hydride (NaH) at or below room temperature followed by additionof a chloride-bridged cyclometallated iridium dimer intermediate{(ppy)₂Ir(μ-Cl)}₂, {(F₂ppy)₂Ir(μ-Cl)}2, {(C6)₂Ir(μ-Cl₂)}₂ or{(piq)₂Ir(μ-Cl)}₂ and heating the reaction mixture. Typically, 2.2equivalents of the N-tosyl- or the unprotected ketopyrrole ligandprecursor was used per mole of the iridium dimer intermediate.

Example 11

Iridium Complex XXVI: To a stirred solution of 2-(4-bromobenzoyl)pyrrole(106 mg, 0.428 mmol) in 2-methoxyethanol (4 mL) was added solid sodiumhydride (40.0 mg, 1.67 mmol) and the resultant yellow solution wasstirred for 5 minutes at ambient temperature. The chloride-bridgedcyclometallated iridium dimer intermediate {(piq)₂Ir(μ-Cl)} 2 (260 mg,0.200 mmol) was then added and the mixture was heated at 70° C. for 1 h.The dark red product mixture was cooled to room temperature and pouredinto MeOH (150 mL) causing the product to precipitate. The productcyclometallated ketopyrrole complex XXVI was collected by filtration,washed with MeOH, and dried in air. Yield (327 mg, 96%). ¹H NMR (400MHz, CD₂Cl₂, 25° C.) δ6.32 (d, 1H), 6.42 (m, 2H), 6.55 (t, 1H), 6.70 (m,1H), 6.79 (m, 1H) 7.01 (m, 2H), 7.18 (d, 1H), 7.44 (d, 1H), 7.56 (d,2H), 7.73 (m, 4H), 7.83 (d, 2H), 7.87 (m, 1H), 7.93 (m, 1H), 8.27 (d,2H), 8.31 (d, 1H), 8.98 (m, 2H); HRMS (MALDI): m/z 849.0899 (100) {M}⁺.

Example 12

Iridium Complex XXVII: 2-(3,5-Dibromobenzoyl)pyrrole (1.31 g, 3.39 mmol)was converted to cyclometallated ketopyrrole complex XXVII as in Example11. The product was collected by filtration, washed with MeOH, and driedin air. Yield (2.74 g, 96%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ6.36 (d,1H), 6.42 (m, 2H), 6.59 (t, 1H), 6.74 (m, 1H), 6.79 (m, 1H) 7.01 (m,2H), 7.18 (m, 1H), 7.35 (d, 1H), 7.46 (d, 1H), 7.54 (d, 1H), 7.75 (m,4H), 7.78 (t, 1H), 7.92 (m, 2H), 8.03 (d, 2H), 8.28 (m, 3H), 9.00 (m,2H); HRMS (MALDI): m/z 928.9338 (100) {M}⁺.

Example 13

Iridium Complex XIV: 2-(3,5-Dimethoxybenzoyl)pyrrole (85.0 mg, 0.367mmol) was converted to cyclometallated ketopyrrole complex XIV as inExample 11. Yield (254 mg, 97%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ3.77(s, 6H), 6.30 (m, 1H), 6.41 (m, 1H), 6.46 (m, 1H), 6.53 (t, 1H), 6.57(t, 1H), 6.73 (m, 1H), 6.79 (m, 1H), 7.00 (m, 4H), 7.18 (m, 1H), 7.34(d, 1H), 7.45 (d, 1H), 7.52 (d, 1H), 7.74 (m, 4H), 7.91 (m, 2H), 8.28(d, 2H), 8.34 (d, 1H), 8.99 (m, 2H); HRMS (MALDI): m/z 831.1916 (100){M}⁺.

Example 14

Iridium Complex XXVIII: To a stirred solution of2-(4-hexylbenzoyl)pyrrole (98.0 mg, 0.385 mmol) in 2-methoxyethanol (5mL) was added sodium hydride (12.0 mg, 0.500 mmol) causing the solutionto turn yellow in color. After letting this solution stir for 5 min,{(piq)₂Ir(μ-Cl)}₂ (200 mg, 0.154 mmol) was added and the mixture wasthen heated at 80° C. for 1.5 hrs. The dark red reaction mixture wascooled to room temperature and poured into MeOH (150 mL) causing theproduct to precipitate. The product was collected by filtration, washedwith MeOH, and dried in air. Yield (248 mg, 98%). ¹H NMR (400 MHz,CD₂Cl₂, 25° C.) δ 0.87 (t, 2H), 1.29 (m, 6H), 1.59 (m, 2H), 2.65 (t,2H), 6.31 (m, 1H), 6.42 (m, 1H), 6.46 (m, 1H), 6.52 (t, 1H), 6.73 (m,1H), 6.79 (m, 1H), 7.00 (m, 2H), 7.20 (m, 1H), 7.25 (d, 2H), 7.31 (d,1H), 7.43 (d, 1H), 7.53 (d, 1H), 7.72 (m, 4H), 7.89 (m, 4H), 8.28 (d,2H), 8.35 (d, 1H), 8.99 (m, 2H); HRMS (MALDI): m/z 855.2345 (100){M}+Yield (248 mg, 98%).

Example 15

Iridium complex XXIX: 2-(4-Methylbenzoyl)pyrrole (71.0 mg, 0.385 mmol)was converted to cyclometallated ketopyrrole complex XXIX as in Example11. Yield (221 mg, 98%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ 2.39 (s,3H), 6.30 (m, 1H), 6.43 (m, 2H), 6.52 (t, 1H), 6.71 (m, 1H), 6.79 (m,1H), 7.00 (m, 2H), 7.18 (m, 1H), 7.25 (d, 2H), 7.32 (d, 1H), 7.44 (d,1H), 7.53 (d, 1H), 7.73 (m, 4H), 7.88 (m, 4H), 8.27 (d, 2H), 8.34 (d,1H), 8.99 (m, 2H); HRMS (MALDI): m/z 785.2699 (100) {M}⁺.

Example 16

Iridium Complex XXX: 2-(4-Methoxybenzoyl)pyrrole (77.0 mg, 0.385 mmol)was converted to cyclometallated ketopyrrole complex XXX as in Example11. Yield (229 mg, 96%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ3.83 (s, 3H),6.30 (m, 1H), 6.42 (m, 2H)<6.50 (t, 1H), 6.73 (m, 1H), 6.78 (m, 1H),6.93 (m, 2H), 7.00 (m, 2H), 7.19 (m, 1H), 7.32 (d, 1H), 7.44 (d, 1H),7.52 (d, 1H), 7.72 (m, 4H), 7.90 (m, 2H), 7.97 (m, 2H), 8.27 (d, 2H),8.34 (d, 1H), 8.98 (m, 2H); HRMS (MALDI): m/z 801.2710 (100) {M}⁺.

Example 17

Iridium Complex XXXI: 2-(4-Fluorobenzoyl)-pyrrole (73.0 mg, 0.385 mmol)was converted to cyclometallated ketopyrrole complex XXXI as in Example11. Yield (228 mg, 97%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ6.32 (m, 1H),6.42 (m, 2H), 6.54 (t, 1H), 6.73 (m, 1H), 6.79 (m, 1H), 7.02 (m, 2H),7.12 (m, 2H), 7.17 (m, 1H), 7.33 (d, 1H), 7.44 (d, 1H), 7.53 (d, 1H),7.73 (m, 4H), 7.88 (m, 2H), 7.98 (m, 2H), 8.27 (m, 2H), 8.32 (d, 1H),8.99 (m, 2H); HRMS (MALDI): m/z 789.2371 (100) {M}⁺.

Example 18

Iridium Complex XXXII: To a stirred solution ofN-toluenesulfonyl-2-(4-trifluoroacetylamino)benzoyl)pyrrole (352 mg,0.806 mmol) in 2-methoxyethanol (4 mL) was added solid sodium hydride(50.0 mg, 2.08 mmol) and the solution was stirred for 5 minutes. Thebridged dimer intermediate {(piq)₂Ir(μ-Cl)}₂ (420 mg, 0.322 mmol) wasthen added and the mixture was heated at 80° C. for 4 hrs. The dark redreaction mixture was cooled to room temperature and concentrated todryness. The product was chromatographed on silica (EtOAc:Hexanes).Yield (355 mg, 69%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ4.08 (bs, 2H),6.28 (m, 1H), 6.41 (m, 3H), 6.65 (d, 2H), 6.72 (m, 1H), 6.78 (m, 1H),7.00 (m, 2H), 7.19 (m, 1H), 7.31 (d, 1H), 7.42 (d, 1H), 7.50 (d, 1H),7.71 (m, 4H), 7.87 (m, 4H), 8.27 (d, 2H), 8.33 (d, 1H), 8.98 (m, 2H);HRMS (MALDI): m/z 786.1066 (100) {M}⁺.

Example 19

Iridium Complex XXXIII:N-Toluenesulfonyl-2-(3,5-di(trifluoroacetylamino)benzoyl)-pyrrole (211mg, 0.385 mmol) was converted to cyclometallated ketopyrrole complexXXXIII as in Example 18. Yield (115 mg, 70%). ¹H NMR (400 MHz, CD₂Cl₂,25° C.) δ3.68 (bs, 4H), 6.11 (t, 1H), 6.29 (m, 1H), 6.43 (m, 2H), 6.51(t, 1H), 6.63 (d, 2H), 6.74 (m, 2H), 7.00 (m, 2H), 7.22 (d, 1H), 7.33(d, 1H), 7.45 (d, 1H), 7.50 (d, 1H), 7.73 (m, 4H), 7.89 (m, 2H), 8.29(m, 3H), 8.98 (m, 2H); HRMS (MALDI): m/z 801.1026 (100) {M}⁺.

Example 20

Iridium complex XXXIV: To a stirred solution of2-(4-aminomethylbenzoyl)pyrrole (106 mg, 0.522 mmol) in DMF (4 mL) wasadded potassium carbonate (62.0 mg, 2.61 mmol) and the yellow solutionwas stirred for 5 minutes. The chloride-bridged iridium dimer{(piq)₂Ir(μ-Cl)}₂ (271 mg, 0.208 mmol) was then added and the mixturewas then heated at 70° C. for 1.5 hrs. The dark red reaction mixture wascooled to room temperature and poured into H₂O (50 mL) causing theproduct to precipitate. The product was collected by filtration, washedwith H₂O, and dried in air and chromatographed on silica (MeOH:CH₂Cl₂).Yield (178 mg, 73%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ3.89 (bs, 2H),6.31 (m, 1H), 6.42 (m, 1H), 6.45 (m, 1H), 6.53 (t, 1H), 6.73 (m, 1H),6.79 (m, 1H), 7.01 (m, 2H), 7.20 (m, 1H), 7.32 (d, 1H), 7.37 (d, 2H),7.44 (d, 1H), 7.53 (d, 1H), 7.72 (m, 4H), 7.89 (m, 4H), 8.28 (d, 2H),8.35 (d, 1H), 8.99 (m, 2H); HRMS (MALDI): m/z 800.0403 (100) {M}⁺.

Example 21

Iridium Complex XXXV: 2-(3,5-Dihydroxybenzoyl)-pyrrole (106 mg, 0.522mmol) was treated at ambient temperature in 2-methoxyethanol (4 mL) withsodium hydride (62.0 mg, 2.61 mmol) and the resultant yellow solutionwas stirred for 5 minutes. The chloride-bridged cyclometallated iridiumdimer intermediate, {(piq)₂Ir(μ-Cl)}₂(271 mg, 0.208 mmol), was added andthe mixture was then heated at 70° C. for 1.5 hrs. The dark red reactionmixture was cooled to room temperature and concentrated to dryness. Theproduct cyclometallated ketopyrrole complex XXXV was chromatographed onsilica (MeOH:CH₂Cl₂, 2:98). Yield (282 mg, 84%). ¹H NMR (400 MHz,CD₂Cl₂, 25° C.) δ5.21 (bs, 2H), 6.31 (m, 1H), 6.41 (m, 3H), 6.55 (t,1H), 6.76 (m, 2H), 6.95 (d, 2H) 7.01 (m, 2H), 7.21 (d, 1H), 7.30 (d,1H), 7.41 (d, 1H), 7.51 (d, 1H), 7.73 (m, 4H), 7.89 (m, 2H), 8.28 (m,3H), 8.98 (m, 2H); HRMS (MALDI): m/z 803.0823 (100) {M}⁺.

Example 22

Iridium Complex XXXVI: To a stirred suspension of iridium complex XXXV(79 mg, 0.098 mmol) in CH₂Cl₂(4 mL) was added triethylamine (100 μL,0.72 mmol). To the resultant homogenous solution was added acryloylchloride (100 μL, 1.2 mmol) and the reaction mixture was stirred for 1hour at room temperature. Thereafter the dark red reaction mixture wasconcentrated to dryness. The crude product was chromatographed on silicagel using CH₂Cl₂ as the eluant. Yield (68 mg, 76%). ¹H NMR (400 MHz,CD₂Cl₂, 25° C.) δ6.02 (m, 2H), 6.27 (d, 1H), 6.31 (d, 1H), 6.35 (m, 1H),6.41 (m, 2H), 6.56 (m, 2H), 6.60 (d, 1H), 6.73 (m, 1H), 6.78 (m, 1H),7.00 (m, 2H), 7.13 (t, 1H), 7.26 (m, 1H), 7.33 (d, 1H), 7.46 (d, 1H),7.52 (d, 1H), 7.66 (d, 2H), 7.74 (m, 4H), 7.90 (m, 2H), 8.27 (d, 2H),8.31 (d, 1H), 8.98 (m, 2H); HRMS (MALDI): m/z 911.1887 (100) {M}⁺.

Example 23

Iridium Complex XXXVII: To a solution of iridium complex XXXV (100 mg,0.492 mmol) in DMF (2.0 mL) were added successively potassium carbonate(272 mg, 1.97 mmol) and allyl bromide (238 mg, 1.97 mmol) at roomtemperature. The mixture was stirred for 24 h, poured into water, andthen extracted with Et₂O. The extract was washed with brine, dried overMg₂SO₄, and concentrated to dryness. The resulting residue waschromatographed on silica gel (CH₂Cl₂) to give the product diallyl etherXXXVII as a colorless oil. Yield (123 mg, 88%). ¹H NMR (400 MHz, CD₂Cl₂,25° C.) δ 4.58 (m, 4H), 5.30 (m, 2H), 5.43 (m, 2H), 6.08 (m, 2H), 6.34(m, 1H), 6.70 (t, 1H), 6.92 (m, 1H), 7.03 (d, 2H), 7.17 (m, 1H), 9.83(bs, 1H); ¹³C NMR (100 MHz, CD₂Cl₂, 25° C.) δ69.7, 106.1, 108.2, 111.5,118.0, 119.7, 125.9, 131.6, 133.7, 140.8, 160.2, 184.4; HRMS (EI): m/z283.1179 (100) {M}⁺.

Example 24

Iridium complex XXXVIII: To a stirred solution of2-(4-bromobenzoyl)-3-methylindole (100 mg, 0.323 mmol) in2-methoxyethanol (4 mL) was added solid sodium hydride (40.0 mg, 1.67mmol) and the mixture was stirred for 5 minutes. {(piq)₂Ir(μ-Cl)}₂(191mg, 0.147 mmol) was then added and the reaction mixture was then heatedat 70° C. for 1.5 hrs. The dark red reaction mixture was cooled to roomtemperature and poured into MeOH/H₂O (125 mL/10 mL) and brought to agentle reflux causing the product to precipitate. The product wascollected by filtration, washed with MeOH, and dried in air. Yield (258mg, 98%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ6.32 (d, 1H), 6.42 (m, 2H),6.55 (t, 1H), 6.70 (m, 1H), 6.79 (m, 1H) 7.01 (m, 2H), 7.18 (d, 1H),7.83 (d, 1H), 7.44 (d, 1H), 7.56 (d, 2H), 7.73 (m, 4H), 7.83 (d, 2H),7.87 (m, 1H), 7.93 (m, 1H), 8.27 (d, 2H), 8.31 (d, 1H), 9.98 (m, 2H);HRMS (MALDI): m/z 913.1481 (100) {M}⁺.

Example 25

Iridium complex XXXIX: To a stirred solution of2-(4-bromobenzoyl)-3-methylindole (132 mg, 0.440 mmol) in2-methoxyethanol (4 mL) was added solid sodium hydride (40.0 mg, 1.67mmol). After stirring for 5 minutes, {(ppy)₂Ir(μ-Cl)}₂ (220 mg, 0.199mmol) was added and the mixture was then heated at 70° C. for 1.5 hrs.The dark red reaction mixture was cooled to room temperature and pouredinto MeOH/H₂O (150 mL/20 mL) causing the product to precipitate. Theproduct was collected by filtration, washed with MeOH, and dried in air.Yield (278 mg, 98%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ6.32 (d, 1H),6.42 (m, 2H), 6.55 (t, 1H), 6.70 (m, 1H), 6.79 (m, 1H) 7.01 (m, 2H),7.18 (d, 1H), 7.83 (d, 1H), 7.44 (d, 1H), 7.56 (d, 2H), 7.73 (m, 4H),7.83 (d, 2H), 7.87 (m, 1H), 7.93 (m, 1H), 8.27 (d, 2H), 8.31 (d, 1H),9.98 (m, 2H); HRMS (MALDI): m/z 813.1268 (100) {M}⁺.

Example 26

Iridium complex XL: To a stirred solution of2-(3,5-dimethoxybenzoyl)pyrrole (85.0 mg, 0.367 mmol) in2-methoxyethanol (4 mL) was added solid sodium hydride (40.0 mg, 1.67mmol). The mixture was stirred for 5 minutes and {(ppy)₂Ir(μ-Cl)}₂(184mg, 0.167 mmol) was added and the mixture was then heated at 70° C. for1 h. The orange reaction mixture was cooled to room temperature andconcentrated to dryness. The product ketopyrrole complex XL waschromatographed on silica (CH₂Cl₂). Yield (230 mg, 94%). ¹H NMR (400MHz, CD₂Cl₂, 25° C.) δ3.81 (s, 6H), 6.34 (m, 3H), 6.61 (m, 2H), 6.76 (m,1H), 6.83 (m, 1H), 6.94 (m, 3H) 7.05 (d, 2H), 7.10 (m, 1H), 7.18 (d,1H), 7.65 (m, 5H), 7.88 (d, 2H), 8.40 (d, 1H); HRMS (MALDI): m/z730.9544 (100) {M}⁺.

Example 27

Iridium complex XLI: To a stirred 2-methoxyethanol solution (4 mL)containing 2-(4-methylbenzoyl)pyrrole (50.0 mg, 0.270 mmol) was addedsolid sodium hydride (13.0 mg, 0.540 mmol) resulting in a yellowsolution that was stirred for 5 min. The chloride-bridgedcyclometallated iridium dimer intermediate {(F₂ppy)₂Ir(μ-Cl)} 2 (153 mg,0.123 mmol) was then added and the mixture was heated at 80° C. for 1.5hrs. The yellow reaction mixture was cooled to room temperature andconcentrated to dryness. The product cyclometallated ketopyrrole complexXLI was chromatographed on silica (Hexanes:CH₂Cl₂, 2:1) andrecrystallized from hexanes:CH₂Cl₂. Yield (120 mg, 65%). ¹H NMR (400MHz, CD₂Cl₂, 25° C.) δ2.41 (s, 3H), 5.80 (m, 1H), 5.82 (t, 1H), 6.36 (m,1H), 6.46 (m, 2H), 6.67 (t, 1H), 7.01 (m, 1H), 7.12 (m, 1H), 7.20 (m,1H), 7.27 (d, 2H), 7.53 (m, 1H), 7.74 (m, 2H), 7.83 (d, 2H), 8.25 (m,2H), 8.36 (m, 1H); HRMS (MALDI): m/z 757.1597 (100) {M}⁺.

Example 28

Iridium Complex XLII: 2-acetylpyrrole (42 mg, 0.385 mmol) was convertedto cyclometallated ketopyrrole complex XLII as in Example 11. Yield (201mg, 92%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ2.52 (s, 3H), 6.21 (m, 1H),6.39 (m, 2H), 6.45 (t, 1H), 6.70 (m, 1H), 6.77 (m, 1H), 6.99 (m, 2H),7.10 (m, 1H), 7.33 (d, 1H), 7.45 (d, 1H), 7.48 (d, 1H), 7.73 (m, 4H),7.90 (m, 2H), 8.26 (m, 3H), 8.95 (m, 2H); HRMS (MALDI): m/z 709.0687(100) {M}⁺.

Example 29

Iridium Complex XLIII: To a stirred 2-methoxyethanol solution (2 mL)containing 2-(3,5-dibromobenzoyl)-pyrrole (139 mg, 0.356 mmol) was addedsolid sodium hydride (40.0 mg, 1.67 mmol) and the resultant yellowsolution was stirred for 5 minutes. The chloride-bridged cyclometallatediridium dimer intermediate {(C6)₂Ir(μ-Cl)}₂(265 mg, 0.142 mmol) was thenadded and the mixture was then heated at 80° C. for 3 hrs. The reactionmixture was cooled to room temperature and poured into MeOH (150 mL)causing the product to precipitate. The product cyclometallatedketopyrrole complex XLIII was collected by filtration and washed withmethanol. The product was chromatographed through silica (CH₂Cl₂). Yield(214 mg, 65%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ2.41 (s, 3H), 5.80 (m,1H), 5.82 (t, 1H), 6.36 (m, 1H), 6.46 (m, 2H), 6.67 (t, 1H), 7.01 (m,1H), 7.12 (m, 1H), 7.20 (m, 1H), 7.27 (d, 2H), 7.53 (m, 1H), 7.74 (m,2H), 7.83 (d, 2H), 8.25 (m, 2H), 8.36 (m, 1H); HRMS (MALDI): m/z1220.0184 (100) {M, M+H}⁺.

Example 30

Iridium complex XLIV: 2-(4-Fluorobenzoyl)-pyrrole (25.0 mg, 0.13 mmol)was converted to cyclometallated ketopyrrole complex XLIV via aprocedure analogous to the procedure described in Example 29. Yield (78mg, 65%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ2.41 (s, 3H), 5.80 (m, 1H),5.82 (t, 1H), 6.36 (m, 1H), 6.46 (m, 2H), 6.67 (t, 1H), 7.01 (m, 1H),7.12 (m, 1H), 7.20 (m, 1H), 7.27 (d, 2H), 7.53 (m, 1H), 7.74 (m, 2H),7.83 (d, 2H), 8.25 (m, 2H), 8.36 (m, 1H); HRMS (MALDI): m/z 1080.1628(100) (M, M+H)⁺.

Preparation of Polymeric Organic Iridium Complexes Example 31

Bisphenol A—Iridium Complex Co-Polycarbonate XLV: To a stirred solutionof bisphenol A bischloroformate (0.500 g, 1.42 mmol), bisphenol A (BPA)(0.323 g, 1.42 mmol), and iridium complex XXXV (28.8 mg, 0.0359 mmol) inmethylene chloride (CH₂Cl₂, 25 mL) 0° C. under a nitrogen atmosphere wasadded triethylamine (0.359 mg, 3.55 mmol). The mixture was maintained at0° C. and stirred for 1 hr. The reaction mixture was then allowed towarm to room temperature and stirring was continued for an additionalhour. The mixture was then diluted with CH₂Cl₂(25 mL) and transferred toa flask containing 10% NaHCO₃(50 mL) and stirred for 10 min. Theresultant two-phase mixture was transferred to a separatory funnel andthe aqueous layer was separated and discarded. The organic phase waswashed with 5% HCl (2×50 mL), then with H₂O (2×50 mL), concentrated to avolume of about 15 mL, and added to MeOH (100 mL) to precipitate theproduct co-polycarbonate. The product was collected by filtration andthen redissolved in CH₂Cl₂(25 mL) and isolated by dropwise addition torapidly stirred, boiling H₂O (300 mL). The product co-polycarbonate wascollected by filtration, dried in air, and again dissolved in CH₂Cl₂(25mL) and precipitated from MeOH. The product co-polycarbonate was driedand analyzed by gel permeation chromatography (relative to polystyrenestandards): M_(w)=108,000 grams per mole, M_(w)=30,000 grams per mole,M_(w)/M_(n)=3.60.

Example 32

Poly(9,9-diocylfluorene) End-capped Organic Iridium Complex XLVI: Asolution of 2,7-dibromo-9,9-dioctylfluorene, 537 mg (0.98 mmol),9,9-dioctylflouren-2,7-diyl-bistrimethyleneborate (558 mg, 1.00 mmol,CAS No. 317802-08-7) and tri-o-tolylphosphine (30.4 mg, 0.1 mmol) intoluene (25 mL) was degassed with argon for 10 minutes. Pd(OAc)₂(6.7 mg,0.03 mmol) and tetraethylammonium hydroxide (2.2 mL of a 20% aqueoussolution, 3.0 mmol) were then added and the resultant mixture wasdegassed for an additional 5-10 minutes. The mixture was then immersedin an oil bath at 80° C. and stirred under a positive nitrogen pressurefor 3 hours. Organic iridium complex XXVI, 34 mg (0.04 mmol) was addedand heating was continued for an additional 18 hours. The reactionmixture was stirred at ambient temperature with 20 mL 0.1N HCl and thenfiltered through CELITE. The organic phase was diluted with toluene(15-20 mL), washed with water (2×25 mL), saturated NaCl (1×25 mL) andthen passed through a filter containing a layer of amine-functionalizedsilica gel and CELITE. The filtrate was concentrated on a rotaryevaporator and the product polymeric organic iridium complex XLVI wasisolated by precipitation into 5 volumes of methanol. The salmon coloredpolymer was redissolved in CH₂Cl₂ and reprecipitated into methanol.Solids were then stirred in a mixture of water and methanol (˜9/1),collected and stirred with methanol for 2 hrs. The iridium complexend-capped polyfluorene XLVI was collected by filtration and dried in avacuum oven. Gel permeation chromatographic analysis indicates Mw=21076and Mw/Mn=2.68.

Example 33

Poly(9,9-diocylfluorene-triarylamine) End-capped Organic Iridium ComplexXLVII: A solution of N,N-4,4′-dibromophenyl-N-4-2-butylphenylamine, 278mg (0.605 mmol), 9,9-dioctyl-2,7-bis-dimethyleneborate, 327 mg (0.6175mmol), and tri-o-tolylphosphine, 18.7 mg (0.0617 mmol) in toluene (15ml) was degassed with argon for 10 minutes then Pd(OAc)₂, 4.2 mg (0.0185mmol) and tetraethylammonium hydroxide, 1.4 ml of a 20% aqueous solution(1.9 mmol) was added and degassing was continued for an additional 5-10minutes. The mixture was immersed in an 70° C. oil bath and stirredunder a positive nitrogen pressure for 2 hours at which point theiridium complex, XXVI {(piq)Ir(L_(A)), where L_(A) is the ancillaryligand derived from 2-(4-bromobenzoyl)pyrrole}, 21 mg (0.0247 mmol) wasadded. Heating was continued for an additional 18 hr and the cooledmixture was stirred with 20 ml of 0.1N HCl then filtered through Celite.The organic phase was diluted with toluene (15-20 ml), washed with water(2×25 ml) and saturated NaCl (1×25 ml) then passed through a filtercontaining a layer of amine-functional silica gel and Celite. Thesolution was concentrated on a rotary evaporator and the polymer wasisolated by precipitation into 5 volumes of methanol. The salmon coloredpolymer was redissolved in CH₂Cl₂ and reprecipitated into methanol.Solids were then stirred in a mixture of water and methanol (˜9/1),collected and stirred with methanol for 2 hrs. The final polymer wascollected by filtration and dried in a vacuum oven. The yield was 279 mg(63.5%). Gel permeation chromatographic analysis indicates Mw=28747grams per mole and Mw/Mn=2.05. ¹H NMR (CDCl₃) δ7.78-7.22 (m, 18, Ar—H),2.65 (t, 1, methine-CH), 2.0 (br s, 4, —CH₂'s) and 1.52-0.82 ppm ((m, 38t, aliphatics). Signals for the complex were undetectable. UV (CH₂Cl₂) λmax=388 nm.

TABLE 21 Data for polymeric organic iridium complex XLVII of Example 33Mw Mn (× 10⁻³) (× 10⁻³) Mw/Mn 28.7 14.0 2.1

Example 34

Deuterated Polymeric Organic Iridium Complex LII: A solution ofdibromide, XLVIII, 482 mg (0.88 mmol), bis-borate XLIX, 530 mg (1.0mmol), arylphenoxazine dibromide, XL, 43 mg (0.1 mmol) andtris-o-tolylphosphine, 32 mg mmol) in toluene (20 ml) was degassed withargon for 15 minutes then Pd(OAc)₂, 7.0 mg (0.031 mmol) and Et₄NOH, 3.7g of a degassed 20% aqueous solution (5.0 mmol) and water, 4 ml, wereadded. Degassing was continued for an additional 5 minutes then theargon tube was replaced with a positive nitrogen pressure, the flask wasimmersed in an 70° C. oil bath. After 20 minutes, deuterated organiciridium complex, LI (incorporating 2 cyclometallated ligands derivedfrom perdeutero 1-phenylisoquinoline), 23 mg (0.02 mmol) was added andstirring under nitrogen was continued for 18 hours. (Organic iridiumcomplex LI was prepared as described in Example 53 below). The cooledmixture was diluted with toluene (10 ml) and stirred with 0.1N HCl (25ml) for 30 minutes. This mixture was filtered through Celite and theorganic phase was washed with 2×25 ml of water and 1×25 ml of saturatedNaCl. After filtration through layers of amine-functional silica gel andCelite, the solution was concentrated to about 10% solids using a rotaryevaporator. The residue was precipitated into methanol (5-10 volumes).Collected solids were redissolved in CH₂Cl₂ and reprecipitated into (1/1v/v) methanol/acetone. The collected solids were boiled with awater/methanol mixture (9/1), collected and stirred with acetone thenmethanol. The final polymer was dried overnight in a vacuum oven at 60°C. to afford 648 mg (84%) of a salmon-colored polymer. Molecular weight(GPC): 90,278, (Mw) Mw/Mn=3.02) UV (CH₂Cl₂) λ_(max)32 391 nm; ¹H NMR(CD₂Cl₂) δ8.0-7.8 (m, ˜12, ArH), 2.20 (s, br, 8, Ar—CH₂) and 1.2-0.8 ppm(m, ˜58, aliphatics). For convenience, the product polymeric organiciridium complex is represented as structure LII. Here, and throughoutthis disclosure, the mole percentages of the various structural unitscomprising the polymers is nominal and is based upon the relativeamounts of reactants employed to prepare the polymer.

Examples 35-37

Co-polyfluorene-triarylamine electroluminescent materials comprisingorganic iridium groups on the polymer main chain were prepared asdescribed in the following general procedure. Molecular weight data forthe polymeric organic iridium complexes LIV, LV, and LVI are gathered inTable 22.

A solution of bis-borate compound XLIX, triarylamine dibromide LIII,iridium complex XXVII, and tris-o-tolylphosphine in toluene (12 mL) wasdegassed with argon via an argon inlet tube for 15 minutes. Pd(OAc)₂(3.4mg, 0.015 mmol) and Et₄NOH (1.0 mL of a degassed 20% aqueous solution,1.36 mmol) were then added and degassing was continued for an additional5 minutes. The reaction flask was then placed under a positive nitrogenpressure, immersed in an 80° C. oil bath and the reaction mixture wasstirred at 80° C. for 18 hours. The reaction mixture then was dilutedwith toluene (10 mL) and stirred with 0.1N HCl (25 mL) for 30 minutes.This mixture was filtered through CELITE and the organic phase waswashed with 2×25 mL of water and 1×25 mL of saturated NaCl. Afterfiltration through layers of amine-functional silica gel and CELITE, thesolution was concentrated to about 10% solids using a rotary evaporator.The residue was precipitated into methanol (5-10 volumes). Collectedsolids were redissolved in CH₂Cl₂ and reprecipitated into methanol. Thecollected solids were boiled with a water/methanol mixture (9/1),collected and stirred with acetone then methanol. The purified productpolymer (LIV, LV, or LVI) was dried overnight in a vacuum oven at 60° C.

TABLE 22 Polymeric Organic Iridium Complexes Comprising Co-Polyfluorene-Triarylamine Structural Units Molar Ratio of StructuralGroups De- rived From Organic Iridium Complex XXVII Structural GroupsEx- Derived From am- Structure Triarylamine Mw Mn ple # # Dibromide LIII(× 10⁻³) (× 10⁻³) Mw/Mn 35 LIV 4:96 48.7 23.3 2.1 36 LV 2:98 53 9.5 5.737 LVI 10:90  41.4 24.6 1.7

Preparation of Deuterated Organic Iridium Complexes Example 38

D₇-Isoquinoline-N-oxide: A mixture of D₇-isoquinoline (2.50 g, 18.4mmol) (C/D/N Isotopes Inc.), 7.5 mL of glacial acetic acid, and 4.5 mLof 30% hydrogen peroxide was heated at reflux for 2.5 h. The mixture wasthen concentrated under reduced pressure and the yellow residue wasdissolved in CHCl₃ and treated with excess of K₂CO₃. Water was added toform a thick paste with the carbonate. The mixture was filtered afterthe cessation of effervescence and the solid paste was washed withCHCl₃. The CHCl₃ solution was dried over K₂CO₃, filtered andconcentrated to dryness to give a yellow-orange oil. The oil wasdissolved in EtOAc (10 mL) and the solvent was cautiously removed on arotary evaporator (without a water bath) until the product solidified.The solid product was suspended in hexanes and collected by vacuumfiltration and dried in air. Yield: 2.50 g, 89%. ¹H NMR (400 MHz,CD₂Cl₂, 25° C.) δ7.56 (bs), 7.60 (bs), 7.66 (bs), 7.70 (bs), 7.79 (bs),8.06 (bs), 8.70 (bs). It is estimated that the product was 97.5%deuterated.

Example 39

D₆-2-Chloroisoquinoline: To a CD₂Cl₂ solution of D₇-isoquinoline-N-oxide(2.50 g, 16.4 mmol) was added dropwise POCl₃(5.0 mL, 53.5 mmol) at sucha rate as to maintain a gentle reflux and then the reaction mixture washeated at reflux for 2 h. The reaction mixture was then cooled and addeddropwise to a rapidly stirred biphasic mixture of NaHCO₃(20g) in 50 mLand Et₂O (100 mL). After the cessation of effervescence the layers wereseparated and the aqueous phase was extracted with ether (3×100 mL). Thecombined organic extracts were dried over MgSO₄ and decolorized withcharcoal. The solvents were removed to afford a mixture of deuterated2-chloroisoquinoline and isoquinoline as a yellow oil. The product wascarried on to the next step (See Example 40) without furtherpurification. Yield: 2.00 g, 72%. ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ7.64(bs), 7.71 (bs), 7.77 (bs), 7.85 (bs), 7.88 (bs), 8.20 (bs), 8.25 (bs).

Example 40

D₅-Phenylboronic acid: A dry three-neck flask equipped with a rubberseptum, an addition funnel equipped with a rubber septum, and acondenser was charged under nitrogen with magnesium turnings. To theaddition funnel was added D₅-bromobenzene (6.5 mL, 62 mmol) (Aldrich)dissolved in a 1:1 mixture of THF/toluene (31 mL). Grignard reagentformation was observed after about after about 1 mL of the contents ofthe addition funnel had been added to the magnesium turnings. Theremaining bromobenzene solution was added dropwise over a period ofabout 1 h. After the addition was complete the reaction mixture washeated at 70° C. for 1 h. The reaction mixture was cooled to roomtemperature and added via a canulating needled to an addition funnel ona second three-neck flask containing a solution of triethylborate(B(OEt)₃) (10.5 mL, 62 mmol) in toluene (10 mL) maintained at 0° C. Thesolution of the freshly prepared Grignard reagent was then addeddropwise to the solution of triethylborate over a period of 1 h. Thecooling bath was then removed and the reaction mixture was allowed tostir at room temperature for 15 h. The reaction mixture was quenchedwith 10% H₂SO₄(30 mL) and stirred at room temperature for 1 h. Thelayers were separated and the organic layer was dried over Na₂SO₄. Afterremoval of the solvents, hexanes were added to precipitate the productas an off-white solid which was collected by filtration and dried.Yield: 3.50 g, 45%. ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ 6.01 (bs, 2H).

D₁₁-2-Phenylisoquinoline: A biphasic mixture of toluene (10 mL), EtOH (5mL), and 2M Na₂CO₃(10 mL) containing D₅-phenylboronic acid (2.40 g, 19.0mmol) and D₆-2-chloroisoquinoline (2.00 g, 11.8 mmol) was purged with N₂for 30 min using a gas diffusion tube. Pd(PPh₃)₄(0.600 g, 0.520 mmol)was then added and the mixture was heated at reflux for 5 h. Aftercooling to room temperature the product mixture was transferred to aseparatory funnel containing H₂O (100 mL) and the layers were separated.The aqueous layer was extracted with EtOAc (2×100 mL) and the combinedorganic layers were washed with H₂O, dried over Na₂SO₄, filtered, andconcentrated to dryness. The crude product was chromatographed(SiO₂EtOAc/Hexanes) to afford the product as a white solid. Yield: 1.50g, 59%. ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ7.34 (bs), 7.35 (bs), 7.55(bs), 7.67 (bs), 7.71 (bs), 7.92 (bs), 8.11 (bs), 8.21 (bs), 8.59 (bs);HRMS (ESI): m/z 217.1862 (100) {M+H}+(98.5 atom % D).

((D₁₀-piq)₂Ir(μ-Cl))₂: A mixture of 2-methoxyethanol and water (20 ml: 5mL) was degassed with N₂ for 15 min. To this solvent mixture was addedIrCl₃.xH₂O (0.94 g, 3.2 mmol) followed by D₁₁-2-phenylisoquinoline (1.5g, 6.9 mmol) and the mixture was heated at reflux for 15 h under anatmosphere of N₂. The reaction mixture was cooled to room temperatureand the red precipitate was collected by filtration and washed with MeOHuntil the filtrate washes were colorless and then dried in air. Yield:1.2 g, 57%. ¹H NMR (400 MHz, CD₃SOCD₃, 25° C.) δ5.56 (s), 6.31 (s), 6.90(s), 6.92 (s), 6.99 (s), 7.01 (s), 8.00-7.80 (m), 8.12 (m), 8.21 (m),8.86 (s), 8.92 (s), 9.57 (s), 9.75 (s).

(D₁₀-piq)₂Ir(L_(A)) LVII: To a stirred 2-methoxyethanol solution (4 mL)containing the 2-(3,5-dimethoxybenzoyl)pyrrole (37 mg, 0.13 mmol) wasadded solid sodium hydride (40.0 mg, 1.67 mmol). After letting thissolution stir for 5 min, ((D₁₀-piq)₂Ir(μ-Cl))₂(100 mg, 0.0745 mmol) wasadded and the mixture was then heated at 80° C. for 1.5 hrs. Thereaction mixture was cooled to room temperature, poured into MeOH (100mL). The product precipitated from solution and was collected by vacuumfiltration. Yield (115 mg, 65%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ3.83(s, 3H), 6.30 (m, 1H), 6.41 (s), 6.44 (s), 6.50 (t, 1H), 6.93 (m, 2H),7.00 (m), 7.19 (m, 1H), 7.32 (s), 7.44 (s), 7.52 (s), 7.72 (s), 7.73(s), 7.74 (s), 7.88 (s), 7.92 (s), 7.97 (m, 2H), 8.27 (t), 8.34 (s),8.98 (m); HRMS (MALDI): m/z 819.2400 (100) {M}⁺.

Performance Characteristics of Organic Iridium Complexes And PolymericOrganic Iridium Complexes in OLED Devices Example 41

The emissive characteristics of organic iridium complex XXVI werecompared to those of dipyrrin complexes LVIII and LIX.

Initially, dilute solutions of dipyrrin complex LVIII in dichloromethaneand organic iridium complex XXVI ((piq)₂Ir(L_(A))) where the ancillaryligand L_(A) is derived from 2-(4-bromobenzoyl)pyrrole indichloromethane were prepared. When the solutions were irradiated at 354nm with a hand-held UV lamp, the vial containing the solution containingorganic iridium complex XXVI was observed to emit an orange-red colorthat was substantially brighter than the deep-red color emitted from thesolution containing dipyrrin complex LVIII.

Next, films were prepared from a xylene solution containing about 3percent by weight of a blue emissive photoluminescent polymer, BP105available from Sumation, and one of the organic iridium complex XXVI,the dipyrrin complex LVIII, or the dipyrrin complex LIX. Thephotoluminescence spectrum of each film was measured using an EdinburghInstruments F920 fluorimeter, with a xenon lamp excitation source thewavelength of which was selected using a monochromator. The bandpass ofthe excitation source was on the order of 1-3 nm and was centered at 390nm. The emitted light was detected using a photomultiplier tube coupledto a single monochromator (with comparable bandpass to the excitationmonochromator) filtered by and additional 3 mm yellow glass plate(Corning 3-73) that served to filter out the primary 390 nm excitationsource. The spectral response of the monochromator and photomultipliertube (PMT) were calibrated against a known spectral standard by themanufacturer (Edinburgh Instruments). The three photoluminescencespectra are shown in FIG. 12.

The difference in the color, i.e., the triplet emission maximum(λ_(max)), for each iridium complex is clearly seen. The organic iridiumcomplex XXVI emitted at a λ_(max) of 613 nm (spectrum labeled 110 solidline in FIG. 12) while both dipyrrin-containing iridium complexes, LIX((ppy)₂Ir(brdip)) and LVIII ((piq)₂Ir(brdip)), emitted at the sameλ_(max) centered at 691 nm (items labeled 120 and 125 in FIG. 12,respectively). The data demonstrate that in dipyrrin-containingcomplexes the emissive triplet energy state is dominated by the dipyrrinligand. The emissive triplet energy state can be said to dominate whenthe wavelength of the emitted light is largely independent of thestructure of the cyclometallated ligand. For example, while mostcomplexes that employ the phenylisoquinoline derived ligand (piq)display a peak emission in the range from about 590 nm to about 630 nm,dipyrrin complexes comprising piq ligands emit at much longerwavelengths, for example a peak emission centered at about 690 nm. Thusit appears that the dipyrrin complexes tend to be limited to lightemission at wavelengths longer than about 690 nm. It has been discoveredthat organic iridium complexes and polymeric organic iridium complexesof the present invention tend to exhibit a peak emission in the rangefrom about 560 nm to about 630 nm, a range considered highly desirableby those skilled in the art, since visible red light emission (fromabout 605 nm to about 620 nm) is highly prized. It has also beenobserved that the organic iridium complexes and polymeric organiciridium complexes of the present invention are tolerant of a variety ofstructural variations and still emit light having a peak emission in therange from about 560 nm to about 630 nm. In one embodiment, the organiciridium compositions of the present invention emit light having a peakemission in the range from about 605 nm to about 620 nm.

The quantum efficiency of energy transfer from the photoluminescentpolymer to the organic iridium complex XXVI was estimated to be about75% by comparing the residual area under the band at 450 nm (itemlabeled 112 in FIG. 12) which corresponds to the blue emissive band forthe photoluminescent polymer to that of the area under bands centered at613 nm which corresponds to the emission from the organic iridiumcomplex XXVI. The corresponding blue emission bands for films comprisingthe dipyrrin complexes (labeled 122 and 127 in FIG. 12) indicate thatlight producing energy transfer from the photoluminescent polymer to thedipyrrin complexes LVIII and LIX is less efficient than to complex XXVI.The results obtained from the film containing organic iridium complexXXVI suggest that energy transfer from the excited statephotoluminescent polymer to the organic iridium complexes of the presentinvention is highly efficient. Moreover, in a variety of embodiments,light emission from the organic iridium complexes of the presentinvention such as XXVI occurs in a highly desirable wavelength rangefrom about 600 nm to about 630 nm.

Example 42

The performance of two organic iridium complexes, XXVII comprising a3,5-dibromobenzoylpyrrolic ancillary ligand and XIV comprising a3,5-dimethoxybenzoylpyrrolic ancillary ligand, was probed by preparingOLED devices comprising one of compounds XXVII and XIV and comparing theOLED devices to an identical OLED device containing the known organiciridium complex (piq)₂Ir(acac). The devices were each prepared asdescribed in Example 44 below and differed only in the chemicalstructure of the organic iridium complex employed. Theelectroluminescence spectrum for each of the OLED devices is shown inFIG. 13. The electroluminescence spectra are normalized so that the peakintensity equals 1 in each spectrum. The electroluminescence spectra maybe conveniently summarized by two parameters, the CIE X and Ycoordinates, which are given in Table 23 below.

TABLE 23 OLED Device Performance as a Function of Organic IridiumComplex Structure Organic Iridiun Complex Substitution Pattern* CIE XCIE Y LPW XIV 3,5-dimethoxy 0.638 0.333 6.21308 (piq)₂Ir(acac) — 0.6550.315 4.64689 XXVII 3,5-dibromo 0.607 0.326 1.04806 *Substitutionpattern on benzoyl moiety of the ketopyrrolic ligand. Thecyclometallated ligands were derived from 1-phenylisoquinoline in eachcaseThe devices containing organic iridium complexes XXVII or XIV exhibitnearly identical electroluminescence spectra (See spectra labeled 130and 132 in FIG. 13. The electroluminescence spectra nearly overlap inthe region 550 nm-750 nm) and the peak maxima are blue shifted relativeto the device containing (piq)₂Ir(acac). The blue shift observed here isnoteworthy in that it results in better eye sensitivity to the emittedlight. It is also interesting to note that the OLED device containingthe organic iridium complex comprising the 3,5-dibromobenzoyl moietyexhibits less overall red emission than does the OLED device containingthe organic iridium complex comprising the 3,5-dimethoxybenzoyl moiety.Thus the benzoyl moiety provides a particularly convenient structuralfeature as the functionality arrayed on the benzoyl moiety may incertain embodiments be varied without changing the emission wavelength.

FIG. 14 provides LPW and relative brightness in candela per Ampere(cd/A) to the brightness of a corresponding device. In principle, theeffective brightness of each device is related to the quantumefficiencies and stabilities of the individual organic iridiumcomplexes. For each of the devices the brightness and current versusapplied voltage were measured using a Keithley 236 Source Measure unitand a silicon diode coupled to a picoammeter (Keithley). The currentresponse of the diode was converted to OLED brightness (cd/m²) throughcalibration of the silicon diode against a Minolta LS 100 Luminancemeter and by measuring the active area of the OLED. FIG. 14 illustratesthe LPW data obtained for each device. FIG. 15 illustrates the “cd/A”brightness data for each device plotted as a function of the appliedvoltage. The cd/A brightness measures how efficiently injected charge isconverted light the eye can see, the LPW is a power efficacy metric (howmuch visible light is generated for a certain amount of input power).The LPW data contains the effect of both the operating voltage and thecharge to visible light conversion efficiency. The data in FIGS. 14 and15 illustrate that the device containing the organic iridium complex XIVhas better luminous efficacy than the (piq)₂Ir(acac) containing device,both in terms of cd/A and LPW.

In the following Examples (Examples 43-52) film layers were typicallyprepared from xylene solutions containing from about 0.1% to about 2%solids. Solutions containing a polymer and an organic iridiumcomposition (dye) typically had a dye to polymer ratio of about 20 partsby weight polymer to 1 parts by weight dye). Care was taken to ensurethat prior to operation of the finished OLED device oxygen and waterwere excluded. Evaporated NaF thicknesses are nominal and vary betweenabout 3.5 nm and about 7 nm (as measured on a calibrated quartz crystalmicrobalance) in the devices presented here.

Reference Example 43

Preparation Of Reference OLED Device Fabricated Without The Inclusion OfAn Iridium Complex: A layer of PEDOT/PSS (Baytron P VP 8000, apoly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) obtained as asolution from HC Starck, Inc.) having a thickness of about 60 nm wasdeposited by spin-coating onto clean, UV-Ozone treated, 2.5 cm×2.5 cmITO patterned glass substrates. The coated substrates were then baked ona hot plate in air for 30 minutes at 160° C. A layer of F8-TFB (anoctylfluorene-triarylamine copolymer obtained from Sumation, Inc.) holetransporter layer having a thickness of about 10-20 nm was thenspin-coated atop the PEDOT/PSS coated substrates. The F8-TFB-PEDOT/PSScoated substrates were then baked on a hot plate in argon for 30 minutesat 160° C. A layer comprised of the electroluminescent polymer BP79blended with SR454 acrylate (obtained from Sartomer, Inc.) was thenspin-coated from a xylene solution atop the F8-TFB layer. The weightratio of BP79 to SR454 acrylate was about 7:3. This layer on the F8TFB-PEDOT/PSS coated substrates was cured by exposing it for 1 minuteunder argon to shortwave ultraviolet radiation from a UVP model R-52G254 nm source UV lamp. The filter of the lamp had been removed and thesubstrates were positioned during curing at a distance of about 0.5 cmdirectly below the UV grid source. The intensity of the lamp was notcalibrated but was estimated to be about 25 mW/cm² at the 254 nmwavelength believed necessary for curing the SR454 acrylate monomer. Theestimated thickness of the cured layer was 40 nm. A final layer of BP157(an electroluminescent polymer available from Sumation) was deposited byspin casting from a xylene solution of the electroluminescent polymer.Following evaporation of the xylene the final layer was a film having athickness of about 40 nm.

The coated substrates were then placed into a bell jar evaporator, andthe system was pumped until a pressure of about 1×10⁻⁶ torr wasobtained. A layer of sodium fluoride about 7 nm thick (as measured via acalibrated quartz crystal microbalance) was then deposited atop thefinal layer of the coated substrates by physical vapor deposition.Subsequently, a layer of aluminum metal about 130 nm thick was depositedatop the sodium fluoride layer by vapor deposition under vacuum to formthe cathode component of the OLED.

Example 44

OLED Device Fabricated With The Inclusion Of Organic Iridium Complex XIVAs A Small Molecule Dopant: An OLED was prepared as described inReference Example 43 except that the final BP 157 polymer layer wasreplaced with a layer that included the red emitting organic iridiumcomplex XIV (i.e. the organic iridium complex comprising cyclometallatedligands derived from 1-phenylisoquinoline and an ancillary ligandderived from 2-(3,5-dimethoxybenzoyl)pyrrole). The film comprisingorganic iridium complex XIV was about 40-50 nm in thickness was preparedby spin casting a xylene solution containing the BP157electroluminescent polymer and organic iridium complex in a weight ratioof to dye of 20:1 (polymer:iridium complex). Following deposition of thelayer containing the polymer and organic iridium complex, a bilayer(NaF, Al) cathode was deposited as in Reference Example 43.

Example 45

OLED Device Fabricated With The Inclusion Of Polymeric Organic IridiumComplex XLVI: An OLED was prepared as in Reference Example 43 exceptthat the final BP 157 polymer layer was replaced with a layer consistingof polymeric organic iridium complex XLVI. The film containing thepolymeric organic iridium complex had a thickness of from about 20 nm toabout 80 nm and was prepared by spin casting a solution of the polymericorganic iridium complex in xylene onto coated substrates. A bilayer(NaF, Al) cathode was deposited as in Reference Example 43.

Reference Example 46

Reference OLED Device Fabricated Without SR454 and Organic IridiumComposition: A layer of PEDOT/PSS on 2.5 cm×2.5 cm ITO patterned glasssubstrates was prepared as described in Reference Example 43. A 10-20 nmthick F8-TFB (Sumation, Inc.) hole transporter layer was thenspin-coated atop the PEDOT/PSS. The F8-TFB-coated substrates were thenbaked on a hot plate in argon for 30 minutes at 160° C. A final layer ofan electroluminescent polymer, BP 209 (Sumation), having a thickness ofapproximately 40-50 nm) was deposited via spin casting from a xylenesolution atop the F8-TFB layer. A bilayer (NaF, Al) cathode wasdeposited as in Reference Example 43 with the exception that the NaFlayer was approximately 3.5 nm in thickness instead of 7 nm. Prior tothe deposition of the final aluminum layer, the multilayer assembly wassubjected to two thermal treatments at about 13° C. that were about 10min in duration, one such treatment just prior to NaF deposition and onefollowing NaF deposition.

Example 47

OLED Device Of Reference Example 46 Including An Additional Layer OfPolymeric Organic Iridium Complex LV: Patterned glass substrates coatedwith F8-TFB/PEDOT/PSS ITO were prepared as in Reference Example 43. Alayer (10-30 nm) of polymeric organic iridium complex LV and SR454acrylate was deposited via spin casting from a xylene solution. Theweight ratio of polymeric organic iridium complex LV to SR454 was about7:3. The layer containing polymeric organic iridium complex and SR454was photo cured under an inert atmosphere using the curing proceduredescribed in Reference Example 43. A final layer of anelectroluminescent polymer, BP 209 (a blue emissive polymer availablefrom Sumation), having a thickness of 40-50 nm was deposited via spincasting from solution atop the cured SR454-polymeric organic iridiumcomplex LV layer. A bilayer (NaF, Al) cathode was deposited as inReference Example 46.

Example 48

OLED Device Of Example 47 Further Comprising An Interlayer Between TheLayer Containing The Polymeric Organic Iridium Complex LV And The BlueEmissive Layer: Patterned glass substrates coated with PEDOT/PSS ITOwere prepared as in Reference Example 43. Next, a layer (approximately10-30 nm thick) containing F8-TFB (Sumation, Inc.) mixed with SR454 (theweight ratio of F8-TFB to SR454 was about 7 to 3) was then deposited byspin-coating from solution and subsequently photo cured as in Example43. Next a layer (10-30 nm) of polymeric organic iridium complex LV andSR454 acrylate was deposited and cured as in Example 47. Next, a secondlayer (approximately 10-30 nm thick) of F8-TFB (Sumation, Inc.) mixedwith SR454 (the weight ratio of F8-TFB to SR454 was about 7 to 3) wasthen spin-coated from solution atop the cured layer containing thepolymeric organic iridium complex LV. This second layer of F8-TFB andSR454 was then photo cured under an inert atmosphere using the curingprocedure described in Reference Example 43 to provide the cured“interlayer”. A final layer of BP 209 of 40-50 nm thickness wasdeposited via spin casting from solution atop the curedF8-TFB-containing interlayer. A bilayer (NaF (3.5 nm), Al (130 nm))cathode was deposited as in Reference Example 46 with the exception thatjust prior to NaF deposition, the polymer layer structure was subjectedto a thermal treatment at about 13° C. of between 10 to 20 min induration.

Example 49

OLED Device: A layer of a hole injecting material, Air Products HILconducting polymer (available from Air Products), approximately 60 nmthick was spin coated at 2000 rpm onto a clean, UV-Ozone treated, 2.5cm×2.5 cm ITO patterned glass substrate and the coated substrate wasthen annealed at 160° C. for 15 minutes under ambient conditions. Next a10-30 nm thick layer of a hole transport material BP-377 (Sumation,Inc.) mixed with SR454 triacrylate (weight ratio 7:3) was spin-coatedatop the hole injecting layer. The coated assembly was then photo curedunder an inert atmosphere using the curing procedure described inReference Example 43. Next a 10-30 nm layer of a mixture of polymericorganic iridium complex LV and SR454 (weight ratio 7:3) was depositedvia spin casting atop the BP-377 containing layer. This assembly wasphoto cured under an inert atmosphere. Next a 20 nm thick layer of amixture a F8-TFB hole transport polymer (Sumation, Inc.) and SR454(weight ratio 7:3) was spin-coated from a xylene solution atop the layercontaining the polymeric organic iridium complex LV and the assembly wasagain photo cured under an inert atmosphere. A final organic layer(40-50 nm thick) of a blue light emitting electroluminescent polymer, BP209 (Sumation), was deposited via spin casting from xylene solution atopthe F8-TFB containing layer. A bilayer (NaF, Al) cathode was depositedas in Reference Example 48.

Example 50

The OLED Device Of Example 49 Wherein The BP 209 Containing LayerFurther Comprised A Deuterated Organic Iridium Complex: A clean,UV-Ozone treated, 2.5 cm×2.5 cm ITO patterned glass substrate coatedwith a first organic layer containing a hole injecting material, AirProducts HIL conducting polymer, a second organic layer containing BP377, a third organic layer containing polymeric organic iridium complexLV, and a fourth organic layer containing F8-TFB was prepared as inExample 49 including all photo curing steps. Next a 40-50 nm film wasdeposited by spin casting a xylene solution of the BP 209 polymer and adeuterated analog of organic iridium complex XXX (comprised D₁₀-piqligands) atop the F8-TFB hole transport layer. The BP 209 polymer andthe organic iridium complex were present in the xylene solution in aweight ratio of about 20 to 1. A bilayer (NaF, Al) cathode was depositedas in Reference Example 49.

Example 51

The OLED Device Of Example 50 Prepared Without A Polymeric OrganicIridium Complex LV: A clean, UV-Ozone treated, 2.5 cm×2.5 cm ITOpatterned glass substrate coated with a first organic layer containingthe hole injecting material and a second organic layer containing BP 377hole transport material was prepared as in Example 49. Next, a 10-30 nmthick layer of F8-TFB (Sumation, Inc.) hole transport material mixedwith SR454 (ratio 7:3) was spin-coated atop the BP 377 containing layer.The assembly was then photo cured under an inert atmosphere using thecuring procedure described in Reference Example 43. A xylene solutioncontaining the blue emissive polymer BP 209 and organic iridium complexXXX in a weight ratio of about 20 to 1 was spin cast atop the F8-TFBcontaining layer. A bilayer (NaF, Al) cathode was deposited as inReference Example 49.

Example 52

The OLED Device Of Example 51 Comprising Deuterated Organic IridiumComplex LVII: A clean, UV-Ozone treated, 2.5 cm×2.5 cm ITO patternedglass substrate coated with a first organic layer containing the holeinjecting material, a second organic layer containing hole transportmaterial BP 377, and a third organic layer containing F8-TFB holetransport material was prepared as in Example 49 including all photocuring steps. Next a 40-50 nm film was deposited by spin casting axylene solution of the blue light emitting electroluminescent polymer BP209 and the deuterated organic iridium complex LVII atop the F8-TFB holetransport layer. The BP 209 polymer and the organic iridium complex werepresent in the xylene solution in a weight ratio of about 20 to 1. Abilayer (NaF, Al) cathode was deposited as in Reference Example 43 withthe exception that the NaF layer was approximately 3.5 nm in thicknessinstead of 7 nm.

Table 24 provides data on the performance of the OLED devices preparedand compares the performance of the OLEDs of reference Examples 43 and46 with the OLEDs of Examples 44, 45, and 47-52 which present variousaspects of the OLED devices provided by the present invention. The colorof light emitted by each OLED device sample was measured using acalibrated spectrometer while operating the device over a range of fromabout 390 nm to about 750 nm at a current density of about 1 mA. Aqualitative assessment of the color is present in the rightmost columnof Table 24. For this qualitative assessment a device was considered“blue” if the integrated intensity in the region between 390 nm-550nm>80% of the total intensity, “red” if the integrated intensity in theregion 390 nm-550 nm was <15% of the total and “red-blue” for otherdevices. The luminous efficiency, Lumens per Watt (LPW), at the 1 mAcurrent density is presented in Table 24 as well. For the LPWmeasurements the luminous output was measured using a silicon diodecalibrated against a Minolta LS100 luminance meter. To convert fromcd/m² as measured on the luminance meter to lumens, a Lambertianemission pattern was assumed and the following equation was used. Theelectrical input was measured using a Keithley 237 Source measure unit.Lumens=(cd/m ²)×(device area)×(π)

TABLE 24 OLED Device Performance Characteristics Example CIE X CIE Y LPWColor of Emitted Light Reference 0.178 0.257 4.9 Blue Example 43 Example44 0.638 0.333 6.2 Red Example 45 0.571 0.336 2.9 Red Reference 0.1370.204 9.0 Blue Example 46 Example 47 0.502 0.309 6.0 Red-Blue Example 480.273 0.238 6.1 Red-Blue Example 49 0.215 0.256 6.0 Red-Blue Example 500.656 0.334 8.5 Red Example 51 0.657 0.333 9.8 Red Example 52 0.6580.332 9.9 Red

The data provided in Table 24 illustrate the suitability of the organiciridium compositions provided by the present invention for use in OLEDdevices and illustrate the unique performance characteristics of OLEDdevices containing such compositions. The organic iridium compositionsof the present invention are especially useful in the reparation of OLEDdevices which exhibit primarily red emission and these OLED devices canhave equivalent or better efficiency (as measured in LPW) than thereference blue devices. Further, by appropriate choice of device design,the ratio of blue fluorescent emission to red phosphorescent emissioncan be varied without a major loss of efficiency.

Example 53

Deuterated Organic Iridium Complex LI: The starting3,5-Bis(4-bromobenzyloxy)benzoic acid LX was prepared according toliterature procedure. (M. Kawa, J. M. Fréchet, Chem. Mater., 1998, 10,286-296). To a stirred suspension of the carboxylic acid LX (8.90 g,18.0 mmol) in a mixture of CH₃CN (30 mL) and CH₂Cl₂(30 mL) was addedtrifluoroacetic anhydride (5.10 mL, 36.0 mmol). In a separate reactionflask, H₃PO₄(1.25 mL, 18.0 mmol) was added at 0° C. with stirring toTFAA (5.10 mL, 36.0 mmol). The mixture was stirred at 0° C. until itbecame homogenous, after which it was added directly to the CH₃CN/CH₂Cl₂solution containing the benzoic acid derivative. The resultant mixturewas stirred for 5 minutes. N-(4-toluenesulfonyl)-pyrrole (4.00 g, 18mmol) was then added and the mixture was stirred at room temperature for10 hrs. Solvents were removed on a rotary evaporator, and the residuewas treated a second time with a mixture of H₃PO₄/TFAA as before. Afterstirring at room temperature for 2 h, the reaction was neutralized byadding a saturated solution of NaHCO₃. Thereafter the mixture wasconcentrated until the product separated from solution. The product2-(3,5-bis(4-bromobenzyloxy)benzoyl)-N-(4-toluenesulfonyl)-pyrrole LXIwas collected by vacuum filtration, washed with water and dried. Thecrude solid was dissolved in EtOAc and decolorized with charcoal. Afterremoval of solvent the resultant solid was recrystallized fromCH₂Cl₂/EtOH to afford the product LXI as fine white needles. (6.30 g,50%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ2.45 (s, 3H), 5.03 (s, 4H), 6.34(t, 1H), 6.58 (m, 1H), 6.79 (t, 1H), 6.98 (d, 2H), 7.30 (d, 4H), 7.39(d, 2H), 7.52 (d, 4H), 7.75 (m, 1H), 7.94 (d, 2H); ¹³C NMR (100 MHz,CD₂Cl₂, 25° C.) δ22.0, 70.1, 107.5, 109.3, 111.3, 122.4, 125.7, 128.8,129.7, 130.0, 130.1, 132.3, 133.2, 136.6, 136.8140.4, 145.8, 160.0,184.0; HRMS (MALDI): m/z 696.1087 (100) (M+H)⁺.

Deuterated Organic iridium complex LI: To a stirred solution of2-(3,5-bis(4-bromobenzyloxy)benzoyl)-N-(4-toluenesulfonyl)-pyrrole LXI(315.0 mg, 0.372 mmol) in 2-methoxyethanol (4 mL) was added solid sodiumhydride (40.0 mg, 1.67 mmol) and the resultant yellow solution wasstirred for 5 minutes. The chloride-bridged deuterated cyclometallatediridium dimer intermediate {(D₁₀-piq)₂Ir(μ-Cl)}₂ (215 mg, 0.160 mmol)was added and the mixture was then heated at 80° C. for 2 h. The darkred reaction mixture was cooled to room temperature and the solventswere removed to dryness. The crude product was chromatographed on silicagel (CH₂Cl₂/Hexanes) to afford deuterated organic iridium complex LI.Yield (250 mg, 67%). ¹H NMR (400 MHz, CD₂Cl₂, 25° C.) δ5.00 (d, 4H),6.29 (m, 1H), 6.41 (s), 6.45 (s), 6.53 (s, 1H), 6.69 (t, 1H), 7.10 (d,2H), 7.28 (d, 4H), 7.49 (d, 4H), 7.72 (m), 7.90 (s), 7.94 (s), 8.28 (m),8.98 (m); HRMS (MALDI): m/z 1159.1722 (100) (M)⁺.

Example 54

Deuterated Organic Iridium Complex LXII: 4-(4-bromobenzyloxy)benzoicacid was prepared analogously to carboxylic acid LX and was converted todeuterated organic iridium complex LXII as in Example 53. Yield (232 mg,80%). ¹H NMR (500 MHz, CD₂Cl₂, 25° C.) δ 5.06 (s, 2H), 6.31 (m, 1H),6.42 (s), 6.45 (s), 6.51 (s, 1H), 7.00 (d, 2H), 7.18 (m, 1H), 7.31 (d,2H), 7.50 (d, 2H), 7.72 (m), 7.88 (s), 7.92 (s), 7.95 (d, 2H), 8.27 (m),8.99 (m); HRMS (MALDI): m/z 975.1735 (100) (M)⁺.

While the disclosure has been illustrated and described in typicalembodiments, it is not intended to be limited to the details shown,since various modifications and substitutions can be made withoutdeparting in any way from the spirit of the present disclosure. As such,further modifications and equivalents of the disclosure herein disclosedmay occur to persons skilled in the art using no more than routineexperimentation, and all such modifications and equivalents are believedto be within the spirit and scope of the disclosure as defined by thefollowing claims.

1. A composition comprising at least one organic iridium complex ofstructure I

wherein each of the ligands

is independently at each occurrence a cyclometallated ligand which maybe the same or different; R¹ is a C₃-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R² isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; and “a” is an integer from0 to
 3. 2. The composition according to claim 1, wherein thecyclometallated ligand is derived from a phenylisoquinoline compoundhaving structure II

wherein R³ is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁴ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; “m” is an integer from 0 to6; and “n” is an integer from 0 to
 5. 3. The composition according toclaim 1, wherein the cyclometallated ligand is derived from a2-phenylpyridine compound having structure III

wherein R⁵ is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁶ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; “p” is an integer from 0 to4; and “q” is an integer from 0 to
 5. 4. The composition according toclaim 1, wherein the cyclometallated ligand is derived from astyrylisoquinoline compound having structure IV

wherein R⁷ is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁸ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; “d” is an integer from 0 to6; and “e” is an integer from 0 to
 5. 5. The composition according toclaim 1, wherein the cyclometallated ligand

is derived from a 1-phenylisoquinoline, a 2-phenylpyridine, a1-styrylisoquinoline, or a combination thereof.
 6. The compositionaccording to claim 1, wherein the cyclometallated ligand is derived from1-phenylisoquinoline.
 7. The composition according to claim 1, whereinthe cyclometallated ligand is derived from 2-phenylpyridine.
 8. Thecomposition according to claim 1, wherein the cyclometallated ligand isderived from 1-styrylisoquinoline.
 9. The composition according to claim1, wherein said complex comprises a ketopyrrole ligand derived from aketopyrrole having structure V

wherein R¹ is a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, ora C₃-C₄₀ cycloaliphatic radical; R² is independently at each occurrencea deuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; and “a” is an integer from 0 to
 3. 10. The compositionaccording to claim 1, wherein said complex comprises a ketopyrroleligand derived from a benzoyl pyrrole compound having structure VI

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁹ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; “a” is an integer from 0 to3; and “s” is an integer from 0 to
 5. 11. The composition according toclaim 1, wherein said organic iridium complex has structure VII

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R³ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁴ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “m” is an integer from 0 to 6;“n” is an integer from 0 to 4; and “s” is an integer from 0 to
 5. 12.The composition according to claim 1, wherein said organic iridiumcomplex has structure IX

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁵ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁶ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “p” is an integer from 0 to 4;“q” is an integer from 0 to 4; and “s” is an integer from 0 to
 5. 13.The composition according to claim 1, wherein said organic iridiumcomplex has structure XI

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁷ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁸ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “d” is an integer from 0 to 6;“e” is an integer from 0 to 5; and “s” is an integer from 0 to
 5. 14. Anelectrophosphorescent composition comprising at least one electroactivehost material and at least one organic iridium complex of structure I

wherein each of the ligands

is independently at each occurrence a cyclometallated ligand which maybe the same or different; R¹ is a C₃-C₄₀ aromatic radical, a C₁-C₅₀aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R² isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; and “a” is an integer from0 to
 3. 15. The electrophosphorescent composition according to claim 14,wherein said organic iridium complex has structure VII

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R³ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁴ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “m” is an integer from 0 to 6;“n” is an integer from 0 to 4; and “s” is an integer from 0 to
 5. 16.The electrophosphorescent composition according to claim 14, whereinsaid organic iridium complex has structure IX

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁵ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁶ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “p” is an integer from 0 to 4;“q” is an integer from 0 to 4; and “s” is an integer from 0 to
 5. 17.The electrophosphorescent composition according to claim 14, whereinsaid organic iridium complex has structure XI

wherein R² is independently at each occurrence a deuterium atom, ahalogen, a nitro group, an amino group, a C₃-C₄₀ aromatic radical, aC₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphatic radical; R⁷ isindependently at each occurrence a deuterium atom, a halogen, a nitrogroup, an amino group, a C₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphaticradical, or a C₃-C₄₀ cycloaliphatic radical; R⁸ is independently at eachoccurrence a deuterium atom, a halogen, a nitro group, an amino group, aC₃-C₄₀ aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀cycloaliphatic radical; R⁹ is independently at each occurrence adeuterium atom, a halogen, a nitro group, an amino group, a C₃-C₄₀aromatic radical, a C₁-C₅₀ aliphatic radical, or a C₃-C₄₀ cycloaliphaticradical; “a” is an integer from 0 to 3; “d” is an integer from 0 to 6;“e” is an integer from 0 to 5; and “s” is an integer from 0 to
 5. 18.The electrophosphorescent composition according to claim 14, wherein theelectroactive host material is a blue light emitting electroluminescentorganic material.
 19. The electrophosphorescent composition according toclaim 18, wherein the organic iridium complex is characterized by alowest accessible triplet state energy T1 and the blue light emittingelectroluminescent organic material is characterized by a lowestaccessible triplet state energy T2, wherein T1 is less than T2.
 20. Theelectrophosphorescent composition according to claim 14, wherein theorganic iridium complex is at least 10 percent deuterated.
 21. Theelectrophosphorescent composition according to claim 14, wherein theorganic iridium complex is at least 60 percent deuterated.
 22. Anorganic iridium complex having structure XIV